private void checkRowIssues(int[][] cells) {
		final int[] set = new int[Board.SIZE];
		for (int i = 0; i < Board.SIZE; i++) {
			if (cells[i].length != Board.SIZE) {
				throw new IllegalArgumentException("Board is not valid.");
			}

			Arrays.fill(set, 0);
			for (int j = 0; j < Board.SIZE; j++) {
				if (cells[i][j] >= 0 && cells[i][j] <= Board.SIZE) {
					int value = cells[i][j];
					if (value != 0) {
						if (set[value - 1] >= 1) {
							throw new IllegalArgumentException("Board is not valid");
						}
						set[value - 1]++;
					}
				} else {
					throw new IllegalArgumentException("Board is not valid");
				}
			}
		}
	}
Checks if board has issues in each row of the board.

@param cells the board
@throws IllegalArgumentException if board contains initial issues
@throws IllegalArgumentException if board contains numbers out of range
jenetics.example/src/main/java/io/jenetics/example/sudoku/Board.java