code: public void mutateEdges(StaticBuffer key, List<Entry> additions, List<Entry> deletions) throws BackendException {
          edgeStore.mutateEntries(key, additions, deletions, storeTx);
      }
docs: Applies the specified insertion and deletion mutations on the edge store to the provided key.
  Both, the list of additions or deletions, may be empty or NULL if there is nothing to be added and/or deleted.
  
  @param key       Key
  @param additions List of entries (column + value) to be added
  @param deletions List of columns to be removed