private boolean isDeleted(ExtendedCell cell) {
    return isDeletedByDeleteFamily(cell) || isDeletedByDeleteColumn(cell)
      || isDeletedByDeleteFamilyVersion(cell) || isDeletedByDeleteColumnVersion(cell);
  }
@param dir Directory to create file in.
@return random filename inside passed <code>dir</code>
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/StoreFileWriter.java