default void modifyColumnFamily(TableName tableName, ColumnFamilyDescriptor columnFamily)
    throws IOException {
    get(modifyColumnFamilyAsync(tableName, columnFamily), getSyncWaitTimeout(),
      TimeUnit.MILLISECONDS);
  }
Modify an existing column family on a table. Synchronous operation. Use
{@link #modifyColumnFamilyAsync(TableName, ColumnFamilyDescriptor)} instead because it returns
a {@link Future} from which you can learn whether success or failure.
@param tableName    name of table
@param columnFamily new column family descriptor to use
@throws IOException if a remote or network exception occurs
hbase-client/src/main/java/org/apache/hadoop/hbase/client/Admin.java