<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _placement_points_generator(self, skyline, width):
 """Returns a generator for the x coordinates of all the placement points on the skyline for a given rectangle. WARNING: In some cases could be duplicated points, but it is faster to compute them twice than to remove them. Arguments: skyline (list):
 Skyline HSegment list width (int, float):
 Rectangle width Returns: generator """
 
        skyline_r = skyline[-1].right
        skyline_l = skyline[0].left

        # Placements using skyline segment left point
        ppointsl = (s.left for s in skyline if s.left+width <= skyline_r)

        # Placements using skyline segment right point
        ppointsr = (s.right-width for s in skyline if s.right-width >= skyline_l)

        # Merge positions
        return heapq.merge(ppointsl, ppointsr)