'Removes a name or names from a policy. If the name removed is the
primary name then the next available alias will be adopted
as the new primary name.
:param aliases: arbitrary number of existing policy names to remove.'

def remove_policy_alias(self, *aliases):

    for alias in aliases:
        policy = self.get_by_name(alias)
        if (not policy):
            raise PolicyError(('No    policy    with    name    %s    exists.' % alias))
        if (len(policy.alias_list) == 1):
            raise PolicyError(('Policy    %s    with    name    %s    has    only    one    name.    Policies    must    have    at    least    one    name.' % (policy, alias)))
        else:
            policy.remove_name(alias)
            del self.by_name[alias.upper()]
