docs: def pix_coord(self, pix_coord):
          """
          :type pix_coord: list
          :param pix_coord: an x,y pixel coordinate, origin = 1
          """
          try:
              pix_coord = list(pix_coord)
          except:
              pass
          if not isinstance(pix_coord, list) or len(pix_coord) != 2:
              raise ValueError("pix_coord needs to be set with an (x,y) coordinate pair, got {}".format(pix_coord))
          x, y = pix_coord
          if not isinstance(x, Quantity):
              x = float(x) * units.pix
          if not isinstance(y, Quantity):
              y = float(y) * units.pix
          self._pix_coord = x, y