code: func (f *FlagSet) Init(name string, errorHandling ErrorHandling) {
  	f.name = name
  	f.envPrefix = EnvironmentPrefix
  	f.errorHandling = errorHandling
  }
docs: // Init sets the name and error handling property for a flag set.
  // By default, the zero FlagSet uses an empty name, EnvironmentPrefix, and the
  // ContinueOnError error handling policy.