void addMap(Map<byte[], List<ExtendedCell>> familyMap) {
    for (Map.Entry<byte[], List<ExtendedCell>> e : familyMap.entrySet()) {
      // 'foreach' loop NOT used. See HBASE-12023 "...creates too many iterator objects."
      int listSize = e.getValue().size();
      // Add all Cells first and then at end, add the family rather than call {@link #add(Cell)}
      // and have it clone family each time. Optimization!
      for (int i = 0; i < listSize; i++) {
        addCell(e.getValue().get(i));
      }
      addFamily(e.getKey());
    }
  }
Append the given map of family-&gt; edits to a WALEdit data structure. This does not write to
the WAL itself. Note that as an optimization, we will stamp the Set of column families into the
WALEdit to save on our having to calculate column families subsequently down in the actual WAL
writing.
@param familyMap map of family -&gt; edits
hbase-server/src/main/java/org/apache/hadoop/hbase/wal/WALEdit.java