code: public boolean hasMapping(String tableName, long baseId, long relatedId) {
  		UserMappingDao userMappingDao = getMappingDao(tableName);
  		return userMappingDao.countByIds(baseId, relatedId) > 0;
  	}
docs: Determine if the base id and related id mapping exists
  
  @param tableName
  mapping table name
  @param baseId
  base id
  @param relatedId
  related id
  @return true if mapping exists
  @since 3.2.0