public boolean isSet(_Fields field) {
    if (field == null) {
      throw new java.lang.IllegalArgumentException();
    }

    switch (field) {
    case NAME:
      return isSetName();
    case ATTRIBUTES:
      return isSetAttributes();
    case CONFIGURATION:
      return isSetConfiguration();
    case BLOCK_SIZE:
      return isSetBlockSize();
    case BLOOMN_FILTER_TYPE:
      return isSetBloomnFilterType();
    case COMPRESSION_TYPE:
      return isSetCompressionType();
    case DFS_REPLICATION:
      return isSetDfsReplication();
    case DATA_BLOCK_ENCODING:
      return isSetDataBlockEncoding();
    case KEEP_DELETED_CELLS:
      return isSetKeepDeletedCells();
    case MAX_VERSIONS:
      return isSetMaxVersions();
    case MIN_VERSIONS:
      return isSetMinVersions();
    case SCOPE:
      return isSetScope();
    case TIME_TO_LIVE:
      return isSetTimeToLive();
    case BLOCK_CACHE_ENABLED:
      return isSetBlockCacheEnabled();
    case CACHE_BLOOMS_ON_WRITE:
      return isSetCacheBloomsOnWrite();
    case CACHE_DATA_ON_WRITE:
      return isSetCacheDataOnWrite();
    case CACHE_INDEXES_ON_WRITE:
      return isSetCacheIndexesOnWrite();
    case COMPRESS_TAGS:
      return isSetCompressTags();
    case EVICT_BLOCKS_ON_CLOSE:
      return isSetEvictBlocksOnClose();
    case IN_MEMORY:
      return isSetInMemory();
    }
    throw new java.lang.IllegalStateException();
  }
Returns true if field corresponding to fieldID is set (has been assigned a value) and false otherwise
hbase-thrift/src/main/java/org/apache/hadoop/hbase/thrift2/generated/TColumnFamilyDescriptor.java