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I purposefully:
because it appears that you want to maintain a level of backward compatibility for now. I have written the code in this PR so that when you decide to update this package to utilize React 16+ with hooks, you will have less work to do.
I tested the "main" version of the component with the current stable branch of React (16.9), and it works as before, with the improvement that it fixes #22 (like #66 does). I have not tested the "optimized" version.