code: public boolean delete(PartitionKey key, Set<String> columns,
        VersionCheckAction checkAction, KeySerDe keySerDe) {
      return delete(key, columns, checkAction, null, keySerDe);
    }
docs: Execute a Delete on HBase, creating the Delete from the key, and the set of
  columns. Only the columns specified in this set will be deleted in the row.
  
  Any DeleteActionModifers registered with registerDeleteModifier will be
  invoked before the Delete is executed.
  
  @param key
  The StorageKey to map to a Put with the entityMapper.
  @param columns
  The set of columns to delete from the row.
  @param checkAction
  A VersionCheckAction that will force this delete to do a
  checkAndDelete against a version count in the row
  @return True if the delete succeeded, False if the put failed due to update
  conflict