'Consume the HINT clause.
Requires one of three options (mirroring the rest of the datastore):
HINT ORDER_FIRST
HINT ANCESTOR_FIRST
HINT FILTER_FIRST
Returns:
True if the hint clause and later clauses all parsed okay'

def __Hint(self):

    if self.__Accept('HINT'):
        if self.__Accept('ORDER_FIRST'):
            self.__hint = 'ORDER_FIRST'
        elif self.__Accept('FILTER_FIRST'):
            self.__hint = 'FILTER_FIRST'
        elif self.__Accept('ANCESTOR_FIRST'):
            self.__hint = 'ANCESTOR_FIRST'
        else:
            self.__Error('Unknown    HINT')
    return self.__AcceptTerminal()
