SSTableWriter writer = cfs.createFlushWriter(columnFamilies.size(), estimatedSize);
for (Map.Entry<DecoratedKey, ColumnFamily> entry : columnFamilies.entrySet())
writer.append(entry.getKey(), entry.getValue());
SSTableReader ssTable = writer.closeAndOpenReader();
logger.info(String.format("Completed flushing %s (%d bytes)",
ssTable.getFilename(), new File(ssTable.getFilename()).length()));
return ssTable;
}