UWP Community Toolkit with source code

"UWP Community Toolkit" is good tool. https://github.com/Microsoft/UWPCommunityToolkit/tree/master

but If we installed it with NuGet, We can not access source code ( I thought ). Now, I only want to use "RadialGauge" only in this toolkit. and I want to modify "RadialGauge" a bit.. then, I started to use RadialGauge with source code without NuGet install.

here is my step.

1. I open New UWP project with C# VS 2017.

2. I installed this code to my "Controls" folder. UWP RadialGauge Source

3. and I make this project.

but No display, Just white UWP windows is opened... Why ? I need help... with my poor UWP knowledge, to resolve is not possible...

Here is project file.

https://www.dropbox.com/s/alvw6wcbiv5itsp/RadialGaugeTest.zip?dl=0