def get_arg(cmds):
if len(cmds) != <NUM_LIT:2>:<EOL><INDENT>raise ValueError('<STR_LIT>' % cmds[<NUM_LIT:0>])<EOL><DEDENT>return cmds[<NUM_LIT:1>]<EOL>
Accepts a split string command and validates its size.

    Args:
      cmds: A split command line as a list of strings.

    Returns:
      The string argument to the command.

    Raises:
      ValueError: If there is no argument.