code: def DEFINE_boolean(  # pylint: disable=invalid-name,redefined-builtin
      name, default, help, flag_values=_flagvalues.FLAGS, module_name=None,
      **args):
    
    DEFINE_flag(_flag.BooleanFlag(name, default, help, **args),
                flag_values, module_name)
docs: Registers a boolean flag.
  
    Such a boolean flag does not take an argument.  If a user wants to
    specify a false value explicitly, the long option beginning with 'no'
    must be used: i.e. --noflag
  
    This flag will have a value of None, True or False.  None is possible
    if default=None and the user does not specify the flag on the command
    line.
  
    Args:
      name: str, the flag name.
      default: bool|str|None, the default value of the flag.
      help: str, the help message.
      flag_values: FlagValues, the FlagValues instance with which the flag will
          be registered. This should almost never need to be overridden.
      module_name: str, the name of the Python module declaring this flag.
          If not provided, it will be computed using the stack trace of this call.
      **args: dict, the extra keyword args that are passed to Flag __init__.