None type in OrderedFlowDict introduces !!null tag

[rafzi]

When a unity asset file contains the following:

dict: {key: }

it is parsed as follows:

dict: {key: !!null ''}

I tried changing the style of the None representer but could not make it work. This only happens when inside OrderedFlowDict, normal None works fine.

[rafzi]

If this cannot be made to work easily, a simple workaround would be to remove all !!null '' sub-strings from the final output stream.