Skip optional parameters where the value is null in custom values

[PaulWay]

Fix #13

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[PaulWay]

I've signed the CLA.

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CLAs look good, thanks!

[noahdietz]

Thanks for the PR and apologies for the slow response.

I'm cool with this implementation. Can you add a test to the process suite for this functionality? There should be other custom value tests you can reference. Then I'll happily merge/release this.

Edit:
I updated your original PR description to include a reference to the issue you opened.

[noahdietz]

Hi @PaulWay will you have a chance to add a test for this? This is helpful work, would love to include it 😃

[PaulWay]

Hi @noahdietz - sorry I haven't got to this; Javascript isn't my strong suit and I don't really understand the test suite. I've got a bit of something mangled together but I really don't know what I'm doing there. Would be happy to share it with you if you can help me get it working.