code: public String getReplacedMazeString(List<Map<Point, Character>> replacements) {
          String[] stringMaze = toStringArray();
          for (Map<Point, Character> replacement : replacements) {
              for (Point p : replacement.keySet()) {
                  int row = p.y;
                  int column = p.x;
                  char c = stringMaze[row].charAt(column);
                  if (c != Symbol.START.value() && c != Symbol.GOAL.value()) {
                      stringMaze[row] = replaceChar(stringMaze[row], column, replacement.get(p));
                  }
              }
          }
          String output = "";
          for (String line : stringMaze) {
              output += String.format("%s%n", line);
          }
          return output;
      }
docs: Generates a string representation of this maze but replacing all the indicated
  points with the characters provided.
  @param replacements list with maps of point-character replacements.
  @return String representation of the maze with the replacements.