Incorrect type-hint in UI layer's check_valid_ref_id() function

[yousefmoazzam]

The function is the following:

httomo/httomo/ui_layer.py

Lines 241 to 263 in 7842bae

	def check_valid_ref_id(
	side_str: str, ref_id: str, v: str, method: MethodWrapper
	) -> None:
	"""Check the reference values are valid
	TODO option to relocate to yaml_checker
	Parameters
	----------
	side_str
	side output string
	ref_id
	reference id
	v
	ref value
	method
	method found from ref
	"""
	if side_str != "side_outputs":
	raise ValueError(
	"Config error: output references must be of the form <id>.side_outputs.<name>"
	)
	if method is None:
	raise ValueError(f"could not find method referenced by {ref_id} in {v}")

Pyright complains about the body of the second if statement, saying the following:

Type analysis indicates code is unreachable

This is understandable, because the type of method in the function signature is MethodWrapper, and so should never be None. Thus, the condition in the if statement will never evaluate to True, and the body will never be executed.

One way to easily fix this is by making method have type Optional[MethodWrapper]. However, some investigation into whether it should ever be None (and possibly investigation in further refactorings in other logic in the UI layer) may be wise before opting for the simplest fix.