vendor: github.com/prometheus/client_golang v1.12.1

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/github.com/googleapis/gax-go/v2/header.go

@@ -0,0 +1,53 @@
+// Copyright 2018, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+package gax
+
+import "bytes"
+
+// XGoogHeader is for use by the Google Cloud Libraries only.
+//
+// XGoogHeader formats key-value pairs.
+// The resulting string is suitable for x-goog-api-client header.
+func XGoogHeader(keyval ...string) string {
+	if len(keyval) == 0 {
+		return ""
+	}
+	if len(keyval)%2 != 0 {
+		panic("gax.Header: odd argument count")
+	}
+	var buf bytes.Buffer
+	for i := 0; i < len(keyval); i += 2 {
+		buf.WriteByte(' ')
+		buf.WriteString(keyval[i])
+		buf.WriteByte('/')
+		buf.WriteString(keyval[i+1])
+	}
+	return buf.String()[1:]
+}