Reduce the cost of serializing ConversionOptions to code, by using a more...

Reduce the cost of serializing ConversionOptions to code, by using a more efficient inspect.util.getqualifiedname, reducing its max_depth and falling back to caching the value in the namespace. The latter step makes it more difficult to run the generated code afterwards, but it should in turn speed up the conversion process. This also adds an extra check to tf_decorator to improve robustness.

PiperOrigin-RevId: 225226256