rebase: remove prometheus from replace

removed prometheus/client_golang and
prometheus/common from replace section
in go.mod as they are not required anymore
to be in replace section.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/github.com/prometheus/common/expfmt/decode.go

@@ -45,7 +45,7 @@ func ResponseFormat(h http.Header) Format {
 
 	mediatype, params, err := mime.ParseMediaType(ct)
 	if err != nil {
-		return FmtUnknown
+		return fmtUnknown
 	}
 
 	const textType = "text/plain"
@@ -53,21 +53,21 @@ func ResponseFormat(h http.Header) Format {
 	switch mediatype {
 	case ProtoType:
 		if p, ok := params["proto"]; ok && p != ProtoProtocol {
-			return FmtUnknown
+			return fmtUnknown
 		}
 		if e, ok := params["encoding"]; ok && e != "delimited" {
-			return FmtUnknown
+			return fmtUnknown
 		}
-		return FmtProtoDelim
+		return fmtProtoDelim
 
 	case textType:
 		if v, ok := params["version"]; ok && v != TextVersion {
-			return FmtUnknown
+			return fmtUnknown
 		}
-		return FmtText
+		return fmtText
 	}
 
-	return FmtUnknown
+	return fmtUnknown
 }
 
 // NewDecoder returns a new decoder based on the given input format.
@@ -75,14 +75,14 @@ func ResponseFormat(h http.Header) Format {
 func NewDecoder(r io.Reader, format Format) Decoder {
 	switch format.FormatType() {
 	case TypeProtoDelim:
-		return &protoDecoder{r: r}
+		return &protoDecoder{r: bufio.NewReader(r)}
 	}
 	return &textDecoder{r: r}
 }
 
 // protoDecoder implements the Decoder interface for protocol buffers.
 type protoDecoder struct {
-	r io.Reader
+	r protodelim.Reader
 }
 
 // Decode implements the Decoder interface.
@@ -90,7 +90,7 @@ func (d *protoDecoder) Decode(v *dto.MetricFamily) error {
 	opts := protodelim.UnmarshalOptions{
 		MaxSize: -1,
 	}
-	if err := opts.UnmarshalFrom(bufio.NewReader(d.r), v); err != nil {
+	if err := opts.UnmarshalFrom(d.r, v); err != nil {
 		return err
 	}
 	if !model.IsValidMetricName(model.LabelValue(v.GetName())) {

vendor/github.com/prometheus/common/expfmt/encode.go

@@ -21,9 +21,10 @@ import (
 	"google.golang.org/protobuf/encoding/protodelim"
 	"google.golang.org/protobuf/encoding/prototext"
 
-	"github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg"
 	"github.com/prometheus/common/model"
 
+	"github.com/munnerz/goautoneg"
+
 	dto "github.com/prometheus/client_model/go"
 )
 
@@ -76,18 +77,18 @@ func Negotiate(h http.Header) Format {
 		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
 			switch ac.Params["encoding"] {
 			case "delimited":
-				return FmtProtoDelim + escapingScheme
+				return fmtProtoDelim + escapingScheme
 			case "text":
-				return FmtProtoText + escapingScheme
+				return fmtProtoText + escapingScheme
 			case "compact-text":
-				return FmtProtoCompact + escapingScheme
+				return fmtProtoCompact + escapingScheme
 			}
 		}
 		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
-			return FmtText + escapingScheme
+			return fmtText + escapingScheme
 		}
 	}
-	return FmtText + escapingScheme
+	return fmtText + escapingScheme
 }
 
 // NegotiateIncludingOpenMetrics works like Negotiate but includes
@@ -109,26 +110,26 @@ func NegotiateIncludingOpenMetrics(h http.Header) Format {
 		if ac.Type+"/"+ac.SubType == ProtoType && ac.Params["proto"] == ProtoProtocol {
 			switch ac.Params["encoding"] {
 			case "delimited":
-				return FmtProtoDelim + escapingScheme
+				return fmtProtoDelim + escapingScheme
 			case "text":
-				return FmtProtoText + escapingScheme
+				return fmtProtoText + escapingScheme
 			case "compact-text":
-				return FmtProtoCompact + escapingScheme
+				return fmtProtoCompact + escapingScheme
 			}
 		}
 		if ac.Type == "text" && ac.SubType == "plain" && (ver == TextVersion || ver == "") {
-			return FmtText + escapingScheme
+			return fmtText + escapingScheme
 		}
 		if ac.Type+"/"+ac.SubType == OpenMetricsType && (ver == OpenMetricsVersion_0_0_1 || ver == OpenMetricsVersion_1_0_0 || ver == "") {
 			switch ver {
 			case OpenMetricsVersion_1_0_0:
-				return FmtOpenMetrics_1_0_0 + escapingScheme
+				return fmtOpenMetrics_1_0_0 + escapingScheme
 			default:
-				return FmtOpenMetrics_0_0_1 + escapingScheme
+				return fmtOpenMetrics_0_0_1 + escapingScheme
 			}
 		}
 	}
-	return FmtText + escapingScheme
+	return fmtText + escapingScheme
 }
 
 // NewEncoder returns a new encoder based on content type negotiation. All
@@ -139,7 +140,13 @@ func NegotiateIncludingOpenMetrics(h http.Header) Format {
 // interface is kept for backwards compatibility.
 // In cases where the Format does not allow for UTF-8 names, the global
 // NameEscapingScheme will be applied.
-func NewEncoder(w io.Writer, format Format) Encoder {
+//
+// NewEncoder can be called with additional options to customize the OpenMetrics text output.
+// For example:
+// NewEncoder(w, FmtOpenMetrics_1_0_0, WithCreatedLines())
+//
+// Extra options are ignored for all other formats.
+func NewEncoder(w io.Writer, format Format, options ...EncoderOption) Encoder {
 	escapingScheme := format.ToEscapingScheme()
 
 	switch format.FormatType() {
@@ -178,7 +185,7 @@ func NewEncoder(w io.Writer, format Format) Encoder {
 	case TypeOpenMetrics:
 		return encoderCloser{
 			encode: func(v *dto.MetricFamily) error {
-				_, err := MetricFamilyToOpenMetrics(w, model.EscapeMetricFamily(v, escapingScheme))
+				_, err := MetricFamilyToOpenMetrics(w, model.EscapeMetricFamily(v, escapingScheme), options...)
 				return err
 			},
 			close: func() error {

vendor/github.com/prometheus/common/expfmt/expfmt.go

@@ -15,6 +15,7 @@
 package expfmt
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/prometheus/common/model"
@@ -34,20 +35,21 @@ const (
 	TextVersion              = "0.0.4"
 	ProtoType                = `application/vnd.google.protobuf`
 	ProtoProtocol            = `io.prometheus.client.MetricFamily`
-	ProtoFmt                 = ProtoType + "; proto=" + ProtoProtocol + ";"
+	protoFmt                 = ProtoType + "; proto=" + ProtoProtocol + ";"
 	OpenMetricsType          = `application/openmetrics-text`
 	OpenMetricsVersion_0_0_1 = "0.0.1"
 	OpenMetricsVersion_1_0_0 = "1.0.0"
 
-	// The Content-Type values for the different wire protocols. Do not do direct
-	// comparisons to these constants, instead use the comparison functions.
-	FmtUnknown           Format = `<unknown>`
-	FmtText              Format = `text/plain; version=` + TextVersion + `; charset=utf-8`
-	FmtProtoDelim        Format = ProtoFmt + ` encoding=delimited`
-	FmtProtoText         Format = ProtoFmt + ` encoding=text`
-	FmtProtoCompact      Format = ProtoFmt + ` encoding=compact-text`
-	FmtOpenMetrics_1_0_0 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_1_0_0 + `; charset=utf-8`
-	FmtOpenMetrics_0_0_1 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_0_0_1 + `; charset=utf-8`
+	// The Content-Type values for the different wire protocols. Note that these
+	// values are now unexported. If code was relying on comparisons to these
+	// constants, instead use FormatType().
+	fmtUnknown           Format = `<unknown>`
+	fmtText              Format = `text/plain; version=` + TextVersion + `; charset=utf-8`
+	fmtProtoDelim        Format = protoFmt + ` encoding=delimited`
+	fmtProtoText         Format = protoFmt + ` encoding=text`
+	fmtProtoCompact      Format = protoFmt + ` encoding=compact-text`
+	fmtOpenMetrics_1_0_0 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_1_0_0 + `; charset=utf-8`
+	fmtOpenMetrics_0_0_1 Format = OpenMetricsType + `; version=` + OpenMetricsVersion_0_0_1 + `; charset=utf-8`
 )
 
 const (
@@ -62,7 +64,7 @@ const (
 type FormatType int
 
 const (
-	TypeUnknown = iota
+	TypeUnknown FormatType = iota
 	TypeProtoCompact
 	TypeProtoDelim
 	TypeProtoText
@@ -70,13 +72,42 @@ const (
 	TypeOpenMetrics
 )
 
+// NewFormat generates a new Format from the type provided. Mostly used for
+// tests, most Formats should be generated as part of content negotiation in
+// encode.go. If a type has more than one version, the latest version will be
+// returned.
+func NewFormat(t FormatType) Format {
+	switch t {
+	case TypeProtoCompact:
+		return fmtProtoCompact
+	case TypeProtoDelim:
+		return fmtProtoDelim
+	case TypeProtoText:
+		return fmtProtoText
+	case TypeTextPlain:
+		return fmtText
+	case TypeOpenMetrics:
+		return fmtOpenMetrics_1_0_0
+	default:
+		return fmtUnknown
+	}
+}
+
+// NewOpenMetricsFormat generates a new OpenMetrics format matching the
+// specified version number.
+func NewOpenMetricsFormat(version string) (Format, error) {
+	if version == OpenMetricsVersion_0_0_1 {
+		return fmtOpenMetrics_0_0_1, nil
+	}
+	if version == OpenMetricsVersion_1_0_0 {
+		return fmtOpenMetrics_1_0_0, nil
+	}
+	return fmtUnknown, fmt.Errorf("unknown open metrics version string")
+}
+
 // FormatType deduces an overall FormatType for the given format.
 func (f Format) FormatType() FormatType {
 	toks := strings.Split(string(f), ";")
-	if len(toks) < 2 {
-		return TypeUnknown
-	}
-
 	params := make(map[string]string)
 	for i, t := range toks {
 		if i == 0 {

vendor/github.com/prometheus/common/expfmt/openmetrics_create.go

@@ -22,11 +22,47 @@ import (
 	"strconv"
 	"strings"
 
+	"google.golang.org/protobuf/types/known/timestamppb"
+
 	"github.com/prometheus/common/model"
 
 	dto "github.com/prometheus/client_model/go"
 )
 
+type encoderOption struct {
+	withCreatedLines bool
+	withUnit         bool
+}
+
+type EncoderOption func(*encoderOption)
+
+// WithCreatedLines is an EncoderOption that configures the OpenMetrics encoder
+// to include _created lines (See
+// https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#counter-1).
+// Created timestamps can improve the accuracy of series reset detection, but
+// come with a bandwidth cost.
+//
+// At the time of writing, created timestamp ingestion is still experimental in
+// Prometheus and need to be enabled with the feature-flag
+// `--feature-flag=created-timestamp-zero-ingestion`, and breaking changes are
+// still possible. Therefore, it is recommended to use this feature with caution.
+func WithCreatedLines() EncoderOption {
+	return func(t *encoderOption) {
+		t.withCreatedLines = true
+	}
+}
+
+// WithUnit is an EncoderOption enabling a set unit to be written to the output
+// and to be added to the metric name, if it's not there already, as a suffix.
+// Without opting in this way, the unit will not be added to the metric name and,
+// on top of that, the unit will not be passed onto the output, even if it
+// were declared in the *dto.MetricFamily struct, i.e. even if in.Unit !=nil.
+func WithUnit() EncoderOption {
+	return func(t *encoderOption) {
+		t.withUnit = true
+	}
+}
+
 // MetricFamilyToOpenMetrics converts a MetricFamily proto message into the
 // OpenMetrics text format and writes the resulting lines to 'out'. It returns
 // the number of bytes written and any error encountered. The output will have
@@ -59,20 +95,34 @@ import (
 // Prometheus to OpenMetrics or vice versa:
 //
 //   - Counters are expected to have the `_total` suffix in their metric name. In
-//     the output, the suffix will be truncated from the `# TYPE` and `# HELP`
-//     line. A counter with a missing `_total` suffix is not an error. However,
+//     the output, the suffix will be truncated from the `# TYPE`, `# HELP` and `# UNIT`
+//     lines. A counter with a missing `_total` suffix is not an error. However,
 //     its type will be set to `unknown` in that case to avoid invalid OpenMetrics
 //     output.
 //
-//   - No support for the following (optional) features: `# UNIT` line, `_created`
-//     line, info type, stateset type, gaugehistogram type.
+//   - According to the OM specs, the `# UNIT` line is optional, but if populated,
+//     the unit has to be present in the metric name as its suffix:
+//     (see https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#unit).
+//     However, in order to accommodate any potential scenario where such a change in the
+//     metric name is not desirable, the users are here given the choice of either explicitly
+//     opt in, in case they wish for the unit to be included in the output AND in the metric name
+//     as a suffix (see the description of the WithUnit function above),
+//     or not to opt in, in case they don't want for any of that to happen.
+//
+//   - No support for the following (optional) features: info type,
+//     stateset type, gaugehistogram type.
 //
 //   - The size of exemplar labels is not checked (i.e. it's possible to create
 //     exemplars that are larger than allowed by the OpenMetrics specification).
 //
 //   - The value of Counters is not checked. (OpenMetrics doesn't allow counters
 //     with a `NaN` value.)
-func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int, err error) {
+func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily, options ...EncoderOption) (written int, err error) {
+	toOM := encoderOption{}
+	for _, option := range options {
+		option(&toOM)
+	}
+
 	name := in.GetName()
 	if name == "" {
 		return 0, fmt.Errorf("MetricFamily has no name: %s", in)
@@ -95,12 +145,15 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int
 	}
 
 	var (
-		n          int
-		metricType = in.GetType()
-		shortName  = name
+		n             int
+		metricType    = in.GetType()
+		compliantName = name
 	)
-	if metricType == dto.MetricType_COUNTER && strings.HasSuffix(shortName, "_total") {
-		shortName = name[:len(name)-6]
+	if metricType == dto.MetricType_COUNTER && strings.HasSuffix(compliantName, "_total") {
+		compliantName = name[:len(name)-6]
+	}
+	if toOM.withUnit && in.Unit != nil && !strings.HasSuffix(compliantName, fmt.Sprintf("_%s", *in.Unit)) {
+		compliantName = compliantName + fmt.Sprintf("_%s", *in.Unit)
 	}
 
 	// Comments, first HELP, then TYPE.
@@ -110,7 +163,7 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int
 		if err != nil {
 			return
 		}
-		n, err = writeName(w, shortName)
+		n, err = writeName(w, compliantName)
 		written += n
 		if err != nil {
 			return
@@ -136,7 +189,7 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int
 	if err != nil {
 		return
 	}
-	n, err = writeName(w, shortName)
+	n, err = writeName(w, compliantName)
 	written += n
 	if err != nil {
 		return
@@ -163,55 +216,89 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int
 	if err != nil {
 		return
 	}
+	if toOM.withUnit && in.Unit != nil {
+		n, err = w.WriteString("# UNIT ")
+		written += n
+		if err != nil {
+			return
+		}
+		n, err = writeName(w, compliantName)
+		written += n
+		if err != nil {
+			return
+		}
+
+		err = w.WriteByte(' ')
+		written++
+		if err != nil {
+			return
+		}
+		n, err = writeEscapedString(w, *in.Unit, true)
+		written += n
+		if err != nil {
+			return
+		}
+		err = w.WriteByte('\n')
+		written++
+		if err != nil {
+			return
+		}
+	}
+
+	var createdTsBytesWritten int
 
 	// Finally the samples, one line for each.
+	if metricType == dto.MetricType_COUNTER && strings.HasSuffix(name, "_total") {
+		compliantName = compliantName + "_total"
+	}
 	for _, metric := range in.Metric {
 		switch metricType {
 		case dto.MetricType_COUNTER:
 			if metric.Counter == nil {
 				return written, fmt.Errorf(
-					"expected counter in metric %s %s", name, metric,
+					"expected counter in metric %s %s", compliantName, metric,
 				)
 			}
-			// Note that we have ensured above that either the name
-			// ends on `_total` or that the rendered type is
-			// `unknown`. Therefore, no `_total` must be added here.
 			n, err = writeOpenMetricsSample(
-				w, name, "", metric, "", 0,
+				w, compliantName, "", metric, "", 0,
 				metric.Counter.GetValue(), 0, false,
 				metric.Counter.Exemplar,
 			)
+			if toOM.withCreatedLines && metric.Counter.CreatedTimestamp != nil {
+				createdTsBytesWritten, err = writeOpenMetricsCreated(w, compliantName, "_total", metric, "", 0, metric.Counter.GetCreatedTimestamp())
+				n += createdTsBytesWritten
+			}
 		case dto.MetricType_GAUGE:
 			if metric.Gauge == nil {
 				return written, fmt.Errorf(
-					"expected gauge in metric %s %s", name, metric,
+					"expected gauge in metric %s %s", compliantName, metric,
 				)
 			}
 			n, err = writeOpenMetricsSample(
-				w, name, "", metric, "", 0,
+				w, compliantName, "", metric, "", 0,
 				metric.Gauge.GetValue(), 0, false,
 				nil,
 			)
 		case dto.MetricType_UNTYPED:
 			if metric.Untyped == nil {
 				return written, fmt.Errorf(
-					"expected untyped in metric %s %s", name, metric,
+					"expected untyped in metric %s %s", compliantName, metric,
 				)
 			}
 			n, err = writeOpenMetricsSample(
-				w, name, "", metric, "", 0,
+				w, compliantName, "", metric, "", 0,
 				metric.Untyped.GetValue(), 0, false,
 				nil,
 			)
 		case dto.MetricType_SUMMARY:
 			if metric.Summary == nil {
 				return written, fmt.Errorf(
-					"expected summary in metric %s %s", name, metric,
+					"expected summary in metric %s %s", compliantName, metric,
 				)
 			}
 			for _, q := range metric.Summary.Quantile {
 				n, err = writeOpenMetricsSample(
-					w, name, "", metric,
+					w, compliantName, "", metric,
 					model.QuantileLabel, q.GetQuantile(),
 					q.GetValue(), 0, false,
 					nil,
@@ -222,7 +309,7 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int
 				}
 			}
 			n, err = writeOpenMetricsSample(
-				w, name, "_sum", metric, "", 0,
+				w, compliantName, "_sum", metric, "", 0,
 				metric.Summary.GetSampleSum(), 0, false,
 				nil,
 			)
@@ -231,20 +318,24 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int
 				return
 			}
 			n, err = writeOpenMetricsSample(
-				w, name, "_count", metric, "", 0,
+				w, compliantName, "_count", metric, "", 0,
 				0, metric.Summary.GetSampleCount(), true,
 				nil,
 			)
+			if toOM.withCreatedLines && metric.Summary.CreatedTimestamp != nil {
+				createdTsBytesWritten, err = writeOpenMetricsCreated(w, compliantName, "", metric, "", 0, metric.Summary.GetCreatedTimestamp())
+				n += createdTsBytesWritten
+			}
 		case dto.MetricType_HISTOGRAM:
 			if metric.Histogram == nil {
 				return written, fmt.Errorf(
-					"expected histogram in metric %s %s", name, metric,
+					"expected histogram in metric %s %s", compliantName, metric,
 				)
 			}
 			infSeen := false
 			for _, b := range metric.Histogram.Bucket {
 				n, err = writeOpenMetricsSample(
-					w, name, "_bucket", metric,
+					w, compliantName, "_bucket", metric,
 					model.BucketLabel, b.GetUpperBound(),
 					0, b.GetCumulativeCount(), true,
 					b.Exemplar,
@@ -259,7 +350,7 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int
 			}
 			if !infSeen {
 				n, err = writeOpenMetricsSample(
-					w, name, "_bucket", metric,
+					w, compliantName, "_bucket", metric,
 					model.BucketLabel, math.Inf(+1),
 					0, metric.Histogram.GetSampleCount(), true,
 					nil,
@@ -270,7 +361,7 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int
 				}
 			}
 			n, err = writeOpenMetricsSample(
-				w, name, "_sum", metric, "", 0,
+				w, compliantName, "_sum", metric, "", 0,
 				metric.Histogram.GetSampleSum(), 0, false,
 				nil,
 			)
@@ -279,13 +370,17 @@ func MetricFamilyToOpenMetrics(out io.Writer, in *dto.MetricFamily) (written int
 				return
 			}
 			n, err = writeOpenMetricsSample(
-				w, name, "_count", metric, "", 0,
+				w, compliantName, "_count", metric, "", 0,
 				0, metric.Histogram.GetSampleCount(), true,
 				nil,
 			)
+			if toOM.withCreatedLines && metric.Histogram.CreatedTimestamp != nil {
+				createdTsBytesWritten, err = writeOpenMetricsCreated(w, compliantName, "", metric, "", 0, metric.Histogram.GetCreatedTimestamp())
+				n += createdTsBytesWritten
+			}
 		default:
 			return written, fmt.Errorf(
-				"unexpected type in metric %s %s", name, metric,
+				"unexpected type in metric %s %s", compliantName, metric,
 			)
 		}
 		written += n
@@ -350,7 +445,7 @@ func writeOpenMetricsSample(
 			return written, err
 		}
 	}
-	if exemplar != nil {
+	if exemplar != nil && len(exemplar.Label) > 0 {
 		n, err = writeExemplar(w, exemplar)
 		written += n
 		if err != nil {
@@ -473,6 +568,49 @@ func writeOpenMetricsNameAndLabelPairs(
 	return written, nil
 }
 
+// writeOpenMetricsCreated writes the created timestamp for a single time series
+// following OpenMetrics text format to w, given the metric name, the metric proto
+// message itself, optionally a suffix to be removed, e.g. '_total' for counters,
+// an additional label name with a float64 value (use empty string as label name if
+// not required) and the timestamp that represents the created timestamp.
+// The function returns the number of bytes written and any error encountered.
+func writeOpenMetricsCreated(w enhancedWriter,
+	name, suffixToTrim string, metric *dto.Metric,
+	additionalLabelName string, additionalLabelValue float64,
+	createdTimestamp *timestamppb.Timestamp,
+) (int, error) {
+	written := 0
+	n, err := writeOpenMetricsNameAndLabelPairs(
+		w, strings.TrimSuffix(name, suffixToTrim)+"_created", metric.Label, additionalLabelName, additionalLabelValue,
+	)
+	written += n
+	if err != nil {
+		return written, err
+	}
+
+	err = w.WriteByte(' ')
+	written++
+	if err != nil {
+		return written, err
+	}
+
+	// TODO(beorn7): Format this directly from components of ts to
+	// avoid overflow/underflow and precision issues of the float
+	// conversion.
+	n, err = writeOpenMetricsFloat(w, float64(createdTimestamp.AsTime().UnixNano())/1e9)
+	written += n
+	if err != nil {
+		return written, err
+	}
+
+	err = w.WriteByte('\n')
+	written++
+	if err != nil {
+		return written, err
+	}
+	return written, nil
+}
+
 // writeExemplar writes the provided exemplar in OpenMetrics format to w. The
 // function returns the number of bytes written and any error encountered.
 func writeExemplar(w enhancedWriter, e *dto.Exemplar) (int, error) {