diff --git a/vendor/go.opentelemetry.io/otel/api/metric/numberkind_string.go b/vendor/go.opentelemetry.io/otel/api/metric/numberkind_string.go
new file mode 100644
index 0000000..e99a874
--- /dev/null
+++ b/vendor/go.opentelemetry.io/otel/api/metric/numberkind_string.go
@@ -0,0 +1,24 @@
+// Code generated by "stringer -type=NumberKind"; DO NOT EDIT.
+
+package metric
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Int64NumberKind-0]
+	_ = x[Float64NumberKind-1]
+}
+
+const _NumberKind_name = "Int64NumberKindFloat64NumberKind"
+
+var _NumberKind_index = [...]uint8{0, 15, 32}
+
+func (i NumberKind) String() string {
+	if i < 0 || i >= NumberKind(len(_NumberKind_index)-1) {
+		return "NumberKind(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _NumberKind_name[_NumberKind_index[i]:_NumberKind_index[i+1]]
+}