docs: def calc_rel_pos_to_parent(canvas, item, handle):
      """This method calculates the relative position of the given item's handle to its parent
  
      :param canvas: Canvas to find relative position in
      :param item: Item to find relative position to parent
      :param handle: Handle of item to find relative position to
      :return: Relative position (x, y)
      """
      from gaphas.item import NW
  
      if isinstance(item, ConnectionView):
          return item.canvas.get_matrix_i2i(item, item.parent).transform_point(*handle.pos)
  
      parent = canvas.get_parent(item)
      if parent:
          return item.canvas.get_matrix_i2i(item, parent).transform_point(*handle.pos)
      else:
          return item.canvas.get_matrix_i2c(item).transform_point(*item.handles()[NW].pos)