def argument(*param_decls, **attrs):
 def decorator(f):
  ArgumentClass = attrs.pop('cls', Argument)
  _param_memo(f, ArgumentClass(param_decls, **attrs))
  return f
 return decorator

def argument ( * param_decls , ** attrs ) : def decorator ( f ) : ArgumentClass = attrs . pop ( 'cls' , Argument ) _param_memo ( f , ArgumentClass ( param_decls , ** attrs ) ) return f return decorator
attaches an argument to the command .