Setting background color on the inner circle for MagicProgressCircle

[pfieffer]

Hello, The library is very useful to me. Thanks.
I had a question. Can we set the background color of the inner circle for MagicProgressCircle. I tried setBackground but that sets the background of the whole view. I hope you got what I am trying to say.
At the moment the background for the inner circle is just hollow.
Is there a method to set that to opaque? If not, can you suggest me some workaround.
Thanks.

[pfieffer]

Here is a screenshot of the hollow inner circle. I would like to make that opaque.