code: @Override
      protected void _from(ObjectInput in) throws IOException,
              ClassNotFoundException {
          // 1: read index def map size
          final int size = in.readInt();
          // size map accordingly
          indexDefinition = sizedHashMap(size);
  
          TableAnnotationDefinition tad;
          for (int i = 0; i < size; ++i) {
              tad = new TableAnnotationDefinition();
              // 1: read the table annotation definition
              tad.readExternal(in);
              // 2: read the number of documents
              final int documentsSize = in.readInt();
              for (int j = 0; j < documentsSize; ++j) {
                  // 1: read each documents index
                  addAnnotationDefinition(tad, in.readInt());
              }
          }
      }
docs: {@inheritDoc}