Using GetThemeValue causes program to stop responding

when using `Styled.GetThemeValue("value")`, the project would compile and run, but would not respond to any requests. this is on blazor server, i have not tested if the same result also happens on blazor wasm.

is `GetThemeValue` meant to be used, since it is not in the documentation?

The reported entry point is `Styled.GetThemeValue("value")` in a Blazor Server project; begin by reproducing the request hang and checking whether the call is supported despite being undocumented. Compare behavior with Blazor WASM only if the project setup permits. Done means requests remain responsive and the intended API usage is documented or clarified.

Written by the indexing model from the issue text.