public byte[] getFilterBytes() {
    setFilterBytes(org.apache.thrift.TBaseHelper.rightSize(filterBytes));
    return filterBytes == null ? null : filterBytes.array();
  }
Returns true if field existence_only is set (has been assigned a value) and false otherwise
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/generated/TGet.java