human
Solve the following python programming problem given the following code:
@util.positional(1)
def command(name, required=(), optional=()):
assistant
#Here is the Python program you requested.

    """Decorator used for declaring commands used on command line.
    Each command of this tool can have any number of sequential required
    parameters and optional parameters.  The required and optional parameters
    will be displayed in the command usage.  Arguments passed in to the command
    are checked to ensure they have at least the required parameters and not
    too many parameters beyond the optional ones.  When there are not enough
    or too few parameters the usage message is generated and the program exits
    with an error code.
    Functions decorated thus are added to commands by their name.
    Resulting decorated functions will have required and optional attributes
    assigned to them so that appear in the usage message.
    Args:
    name: Name of command that will follow the program name on the command line.
    required: List of required parameter names as displayed in the usage
    message.
    optional: List of optional parameter names as displayed in the usage
    message.
    """
    def check_params_decorator(function):
        def check_params_wrapper(options, *args):
            if (not (len(required) <= len(args) <= (len(required) + len(optional)))):
                sys.stderr.write(("Incorrect    usage    for    command    '%s'\n\n" % name))
                usage()
            function(options, *args)
        check_params_wrapper.required = required
        check_params_wrapper.optional = optional
        commands[name] = check_params_wrapper
        return check_params_wrapper
    return check_params_decorator