code: def find_path(self, start, end, grid):
          
          start.g = 0
          start.f = 0
          return super(AStarFinder, self).find_path(start, end, grid)
docs: find a path from start to end node on grid using the A* algorithm
          :param start: start node
          :param end: end node
          :param grid: grid that stores all possible steps/tiles as 2D-list
          :return: