code: func (f *Factory) BindFlags(flags *pflag.FlagSet) {
  	// any flags defined by external projects (not part of pflags)
  	flags.AddGoFlagSet(flag.CommandLine)
  
  	// Merge factory's flags
  	flags.AddFlagSet(f.flags)
  
  	// Globally persistent flags across all subcommands.
  	// TODO Change flag names to consts to allow safer lookup from subcommands.
  	// TODO Add a verbose flag that turns on glog logging. Probably need a way
  	// to do that automatically for every subcommand.
  	flags.BoolVar(&f.clients.matchVersion, FlagMatchBinaryVersion, false, "Require server version to match client version")
  
  	// Normalize all flags that are coming from other packages or pre-configurations
  	// a.k.a. change all "_" to "-". e.g. glog package
  	flags.SetNormalizeFunc(util.WordSepNormalizeFunc)
  }
docs: // BindFlags adds any flags that are common to all kubectl sub commands.