protected Connection getSQLConnection(PooledConnection poolC) throws SQLException {
    Connection connection;
    try {
      connection = poolC.getConnection();
    } catch (SQLException e) {
      provider.returnAndExpireConnection(poolC);
      throw e;
    }
    boolean val = validateConnection(connection);
    if (val) {
      return connection;
    } else {
      provider.returnAndExpireConnection(poolC);
      throw new SQLException(
          "GemFireConnPooledDataSource::getConnFromConnPool:java.sql.Connection obtained is invalid");
    }
  }
gets the connection from the pool

@return ???
geode-core/src/main/java/org/apache/geode/internal/datasource/GemFireTransactionDataSource.java