'Initialize the subcommand with its parser
This method will automatically add all the arguments described in
``self.args``. Subclasses can perform any additional customizations
on ``self.parser``.'

def __init__(self, parser):

    self.parser = parser
    args = getattr(self, 'args', ())
    for arg in args:
        flags = arg[0]
        if (not isinstance(flags, tuple)):
            flags = (flags,)
        self.parser.add_argument(*flags, **arg[1])
