Bug: Dill get source string from udf not always work

[HaoXuAI]

Expected Behavior

The dill get source for udf_string won't work if the udf is passed as a param to class. This forces the feature view classes to pass in udf_string instead of infer udf_string from the function.
We need to figure out a way to properlt get the source string for udf.

Current Behavior

Steps to reproduce

Specifications

• Version:
• Platform:
• Subsystem:

Possible Solution

[franciscojavierarceo]

Can you provide a link to the code somewhere? Maybe @jitendra or @ntkathole can take a look.