def namedb_state_transition_sanity_check( opcode, op_data, history_id, cur_record, record_table ):
    """
    Sanity checks: make sure that:
    * the opcode and op_data are consistent with one another.
    * the history_id, cur_record, and record_table are consistent with one another.

    Return True if so.
    Raise an exception if not.

    DO NOT CALL THIS METHOD DIRECTLY.
    """

    namedb_op_sanity_check( opcode, op_data, cur_record )

    if opcode in OPCODE_NAME_STATE_TRANSITIONS:
        # name state transition 
        assert record_table == "name_records", "BUG: name state transition opcode (%s) on table %s" % (opcode, record_table)
        assert cur_record.has_key('name'), "BUG: name state transition with no name"
        assert op_data.has_key('name'), "BUG: name state transition with no name"
        assert op_data['name'] == history_id, 'BUG: name op data is for the wrong name ({} != {})'.format(op_data['name'], history_id)
        assert op_data['name'] == cur_record['name'], 'BUG: name op data is for the wrong name ({} != {})'.format(op_data['name'], cur_record['name'])
        assert cur_record['name'] == history_id, "BUG: history ID '%s' != '%s'" % (history_id, cur_record['name'])

    elif opcode in OPCODE_NAMESPACE_STATE_TRANSITIONS:
        # namespace state transition 
        assert record_table == "namespaces", "BUG: namespace state transition opcode (%s) on table %s" % (opcode, record_table)
        assert cur_record.has_key('namespace_id'), "BUG: namespace state transition with no namespace ID"
        assert cur_record['namespace_id'] == history_id, "BUG: history ID '%s' != '%s'" % (history_id, cur_record['namespace_id'])
        assert op_data['namespace_id'] == history_id, 'BUG: name op data is for the wrong name ({} != {})'.format(op_data['namespace_id'], history_id)
        assert op_data['namespace_id'] == cur_record['namespace_id'], 'BUG: name op data is for the wrong name ({} != {})'.format(op_data['namespace_id'], cur_record['namespace_id'])
        assert cur_record['namespace_id'] == history_id, "BUG: history ID '%s' != '%s'" % (history_id, cur_record['namespace_id'])

    assert cur_record.has_key('block_number'), 'BUG: name state transition with no block number'
    if op_data.has_key('block_number'):
        assert op_data['block_number'] == cur_record['block_number'], 'BUG: block number mismatch ({} != {})'.format(op_data['block_number'], cur_record['block_number'])

    return True