'Validate persona value.
If the passed in persona_value is not valid, raise InvalidInput,
otherwise return the persona ID.
:param persona_value:
:raises exception.InvalidInput:
:returns: persona ID'

def validate_persona(self, persona_value):

    if (persona_value not in self.valid_persona_values):
        err = (_("Must    specify    a    valid    persona    %(valid)s,value    '%(persona)s'    is    invalid.") % {'valid': self.valid_persona_values, 'persona': persona_value})
        LOG.error(err)
        raise exception.InvalidInput(reason=err)
    persona_id = persona_value.split('    ')
    return persona_id[0]
