public boolean isSetScannerId() {
      return org.apache.thrift.EncodingUtils.testBit(__isset_bitfield, __SCANNERID_ISSET_ID);
    }
Returns true if field scannerId is set (has been assigned a value) and false otherwise
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/generated/THBaseService.java