Map<R, Map<C, V>> rows = Maps.newLinkedHashMap();
    for (R row : rowSpace) {
      rows.put(row, new LinkedHashMap<C, V>());
    }
    Map<C, Map<R, V>> columns = Maps.newLinkedHashMap();
    for (C col : columnSpace) {
      columns.put(col, new LinkedHashMap<R, V>());
    }
    int[] cellRowIndices = new int[cellList.size()];
    int[] cellColumnInRowIndices = new int[cellList.size()];

/**
 * Implementation of {@code Table} whose iteration ordering across row keys is sorted by their
 * natural ordering or by a supplied comparator. Note that iterations across the columns keys for a
 * single row key may or may not be ordered, depending on the implementation. When rows and columns
 * are both sorted, it's easier to use the {@link TreeBasedTable} subclass.
 *
 * <p>The {@link #rowKeySet} method returns a {@link SortedSet} and the {@link #rowMap} method

 * order of the various views.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in

       * documented in the Javadoc. If a row Comparator is provided, cellSet() iterates across the
       * columns in the first row, the columns in the second row, etc. If a column Comparator is
       * provided but a row Comparator isn't, cellSet() iterates across the rows in the first
       * column, the rows in the second column, etc.
       */
      Comparator<Cell<R, C, V>> comparator =

 * order of the various views.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in

  private static final ImmutableSet<Integer> COLUMN_SPACE = ImmutableSet.of(1, 2);

  private static final SparseImmutableTable<Character, Integer, String> SPARSE =
      new SparseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  private static final DenseImmutableTable<Character, Integer, String> DENSE =
      new DenseImmutableTable<>(CELLS.asList(), ROW_SPACE, COLUMN_SPACE);

  @Override

     * @param line The one-based index of the line containing the problem or {@code -1} if unknown.
     * @param column The one-based index of the column containing the problem or {@code -1} if unknown.
     * @param cause The cause of the problem, may be {@code null}.
     */
    void add(Problem.Severity severity, String message, int line, int column, Exception cause);

    /**

     */
    int getLineNumber();

    /**
     * Gets the one-based index of the column containing the problem. The column number should refer to some text file
     * that is given by {@link #getSource()}.
     *
     * @return the one-based index of the column containing the problem or non-positive value if unknown
     */
    int getColumnNumber();

    /**

    public void setSource(String source) {
        this.source = source;
    }

    @Override
    public void add(Problem.Severity severity, String message, int line, int column, Exception cause) {
        Problem problem = new DefaultProblem(message, severity, source, line, column, cause);

        problems.add(problem);
    }

     * returns -1 if none is available.
     * @return the current line number
     */
    int getLineNumber();

    /**
     * Return the column number where the current event ends,
     * returns -1 if none is available.
     * @return the current column number
     */
    int getColumnNumber();

    /**
     * Return the byte or character offset into the input source this location