@Override
  public int hashCode() {
    int hashCode = 1;

    hashCode = hashCode * 8191 + ((isSetName()) ? 131071 : 524287);
    if (isSetName())
      hashCode = hashCode * 8191 + name.hashCode();

    hashCode = hashCode * 8191 + maxVersions;

    hashCode = hashCode * 8191 + ((isSetCompression()) ? 131071 : 524287);
    if (isSetCompression())
      hashCode = hashCode * 8191 + compression.hashCode();

    hashCode = hashCode * 8191 + ((inMemory) ? 131071 : 524287);

    hashCode = hashCode * 8191 + ((isSetBloomFilterType()) ? 131071 : 524287);
    if (isSetBloomFilterType())
      hashCode = hashCode * 8191 + bloomFilterType.hashCode();

    hashCode = hashCode * 8191 + bloomFilterVectorSize;

    hashCode = hashCode * 8191 + bloomFilterNbHashes;

    hashCode = hashCode * 8191 + ((blockCacheEnabled) ? 131071 : 524287);

    hashCode = hashCode * 8191 + timeToLive;

    return hashCode;
  }
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/thrift/generated/ColumnDescriptor.java