kubernetes/vendor/go.uber.org/zap/flag.go

// 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 { … }