<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def validate_uuid_representation(dummy, value):
 """Validate the uuid representation option selected in the URI. """

    try:
        return _UUID_REPRESENTATIONS[value]
    except KeyError:
        raise ValueError("%s is an invalid UUID representation. "
                         "Must be one of "
                         "%s" % (value, tuple(_UUID_REPRESENTATIONS)))