code: function Fixed2DArray(rows, cols, defaultValue) {
    if(rows <= 0 || cols <= 0){
      throw new Error('fixed-2d-array: Must have more then 0 rows and 0 columns.');
    }
  
    this._width = cols;
    this._height = rows;
    this._grid = [];
  
    for (var i = 0; i < rows; i++) {
      this._grid[i] = [];
      for (var j = 0; j < cols; j++) {
        this._grid[i][j] = defaultValue;
      }
    }
  }
docs: An array with a fixed height and width.
  
  @param row {number} number of rows, corresponds to the height.
  @param cols {number} number of columns, corresponds to the width.
  @param defaultValue the initial value for the array elements
  @class