draw empty histogram in time series

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Above is what I am trying to achieve.

It is a time series plot. I want to make histogram which may overlapping. I would think to draw each vertical & horizontal lines to compose the whole plot, because then I can clearly see the overlapping histogram.

But my question is, how do I draw vertical lines from (timeValue_1, y1) to (timeValue_1, y2) ? All timeseries plot are with different timeValue to connect dots.