code: void put(int row, int column, @NonNull TObj item) {
          SparseArrayCompat<TObj> array = mData.get(row);
          if (array == null) {
              array = new SparseArrayCompat<>();
              array.put(column, item);
              mData.put(row, array);
          } else {
              array.put(column, item);
          }
      }
docs: Put item to the matrix in row, column position.
  
  @param row    item row position
  @param column item column  position
  @param item   Object