diff --git a/vendor/go.uber.org/zap/flag.go b/vendor/go.uber.org/zap/flag.go
new file mode 100644
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+++ b/vendor/go.uber.org/zap/flag.go
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+// Copyright (c) 2016 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package zap
+
+import (
+	"flag"
+
+	"go.uber.org/zap/zapcore"
+)
+
+// LevelFlag uses the standard library's flag.Var to declare a global flag
+// with the specified name, default, and usage guidance. The returned value is
+// a pointer to the value of the flag.
+//
+// If you don't want to use the flag package's global state, you can use any
+// non-nil *Level as a flag.Value with your own *flag.FlagSet.
+func LevelFlag(name string, defaultLevel zapcore.Level, usage string) *zapcore.Level {
+	lvl := defaultLevel
+	flag.Var(&lvl, name, usage)
+	return &lvl
+}