conn = getConnection(env, conn);
if (conn == null) conn = getConnection(env);
  public Value mysql_db_query(Env env,                              String databaseName,                              String query,                              @Optional Mysqli conn)    throws Throwable  {    conn = getConnection(env, conn);        if (conn.select_db(databaseName))      return conn.query(query, 0);    else      return BooleanValue.FALSE;  }