'Generate a ``CREATE GENERATOR`` statement for the sequence.'

def visit_create_sequence(self, create):

    if (create.element.start is not None):
        raise NotImplemented("Firebird    SEQUENCE    doesn't    support    START    WITH")
    if (create.element.increment is not None):
        raise NotImplemented("Firebird    SEQUENCE    doesn't    support    INCREMENT    BY")
    if self.dialect._version_two:
        return ('CREATE    SEQUENCE    %s' % self.preparer.format_sequence(create.element))
    else:
        return ('CREATE    GENERATOR    %s' % self.preparer.format_sequence(create.element))
