protected void initializeTable(Connection connection, TableName tableName) throws IOException {
    if (this.table != null || this.connection != null) {
      LOG.warn("initializeTable called multiple times. Overwriting connection and table "
        + "reference; TableInputFormatBase will not close these old references when done.");
    }
    this.table = connection.getTable(tableName);
    this.regionLocator = connection.getRegionLocator(tableName);
    this.connection = connection;
  }
Allows subclasses to initialize the table information.
@param connection The Connection to the HBase cluster. MUST be unmanaged. We will close.
@param tableName  The {@link TableName} of the table to process.
hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/mapred/TableInputFormatBase.java