code: private static Cell convertKv(Cell kv, Map<byte[], byte[]> cfRenameMap) {
      if(cfRenameMap != null) {
        // If there's a rename mapping for this CF, create a new KeyValue
        byte[] newCfName = cfRenameMap.get(CellUtil.cloneFamily(kv));
        if(newCfName != null) {
            kv = new KeyValue(kv.getRowArray(), // row buffer 
                    kv.getRowOffset(),        // row offset
                    kv.getRowLength(),        // row length
                    newCfName,                // CF buffer
                    0,                        // CF offset 
                    newCfName.length,         // CF length 
                    kv.getQualifierArray(),   // qualifier buffer
                    kv.getQualifierOffset(),  // qualifier offset
                    kv.getQualifierLength(),  // qualifier length
                    kv.getTimestamp(),        // timestamp
                    KeyValue.Type.codeToType(kv.getTypeByte()), // KV Type
                    kv.getValueArray(),       // value buffer 
                    kv.getValueOffset(),      // value offset
                    kv.getValueLength());     // value length
        }
      }
      return kv;
    }
docs: helper: create a new KeyValue based on CF rename map