code: public MatrixSize readMatrixSize(MatrixInfo info) throws IOException {
          // Always read the matrix size
          int numRows = getInt(), numColumns = getInt();
  
          // For coordinate matrices we also read the number of entries
          if (info.isDense())
              return new MatrixSize(numRows, numColumns, info);
          else {
              int numEntries = getInt();
              return new MatrixSize(numRows, numColumns, numEntries);
          }
      }
docs: Reads in the size of a matrix. Skips initial comments