code: public static AbstractUseParser newInstance(final DatabaseType dbType, final ShardingRule shardingRule, final LexerEngine lexerEngine) {
          switch (dbType) {
              case H2:
              case MySQL:
                  return new MySQLUseParser(lexerEngine);
              default:
                  throw new UnsupportedOperationException(String.format("Cannot support database [%s].", dbType));
          }
      }
docs: Create use parser instance.
  
  @param dbType database type
  @param shardingRule databases and tables sharding rule
  @param lexerEngine lexical analysis engine.
  @return use parser instance