public void initFromRows()

in src/main/java/com/twitter/sbf/core/SparseBinaryMatrix.java [119:175]
57 lines of code
13 McCabe index (conditional complexity)

  public void initFromRows(SimpleIterator<String> lines) {
    this.reset();
    int rowId = 0;
    Optional<String> lineOpt;
    Int2ObjectMap<IntArrayList> colsMap = new Int2ObjectOpenHashMap<>();
    int maxColId = -1;
    while (true) {
      lineOpt = lines.next();
      if (!lineOpt.isPresent()) {
        break;
      } else {
        String line = lineOpt.get().trim();
        if (!line.isEmpty()) {
          String[] tokens = line.split("\\s+");
          int[] row = new int[tokens.length];
          for (int i = 0; i < tokens.length; i++) {
            int colId = Integer.parseInt(tokens[i]) - 1; // convert to 0-based
            if (colId < 0) {
              throw new RuntimeException(
                String.format(
                  "Column %d smaller than 1, in line number %d, line:'%s'",
                    colId + 1, rowId + 1, line
                )
              );
            }
            row[i] = colId;
            if (!colsMap.containsKey(colId)) {
              colsMap.put(colId, new IntArrayList());
            }
            colsMap.get(colId).add(rowId);
            if (colId > maxColId) {
              maxColId = colId;
            }
          }
          Arrays.sort(row);
          this.rows[rowId] = row;
        }
        rowId++;
        if (rowId > this.numRows) {
          throw new RuntimeException(
              "More rows in input rows file than the expected " + this.numRows
          );
        }
      }
    }
    if (maxColId > this.numCols) {
      this.numCols = maxColId + 1;
      this.cols = new IntSet[this.numCols];
    }
    for (int colId = 0; colId < this.numCols; colId++) {
      if (colsMap.containsKey(colId) && !colsMap.get(colId).isEmpty()) {
        this.cols[colId] = new IntOpenHashSet(colsMap.get(colId));
      } else {
        this.cols[colId] = new IntOpenHashSet();
      }
    }
  }