def contains(self, point):
    """
    Tests if a point on or within a bounding box.

    Returns: boolean
    """
    return (
          point[0] >= self.minpt[0] 
      and point[1] >= self.minpt[1]
      and point[2] >= self.minpt[2] 
      and point[0] <= self.maxpt[0] 
      and point[1] <= self.maxpt[1]
      and point[2] <= self.maxpt[2]
    )