code: public void addExpiringColumn(ByteBuffer name, ByteBuffer value, long timestamp, int ttl, long expirationTimestampMS) throws IOException
      {
          addColumn(new BufferExpiringCell(metadata.comparator.cellFromByteBuffer(name), value, timestamp, ttl, (int)(expirationTimestampMS / 1000)));
      }
docs: Insert a new expiring column to the current row (and super column if applicable).
  @param name the column name
  @param value the column value
  @param timestamp the column timestamp
  @param ttl the column time to live in seconds
  @param expirationTimestampMS the local expiration timestamp in milliseconds. This is the server time timestamp used for actually
  expiring the column, and as a consequence should be synchronized with the cassandra servers time. If {@code timestamp} represents
  the insertion time in microseconds (which is not required), this should be {@code (timestamp / 1000) + (ttl * 1000)}.