One more case in `utbot-python-types` subtype checker

[tochilinak]

Description

Added support for such protocols:

class SupportsCall(Protocol):
    def __call__(self, *args, **kwargs):
        ...

class HasF(Protocol):
    f: SupportsCall

class SupportsSpecificCall(Protocol):
    def __call__(self, *args, **kwargs) -> HasF:
        ...

class HasSpecificF(Protocol):
    f: SupportsSpecificCall

Example of class that supports HasF but not HasSpecificF:

class S:
    def f(self, x: Union[int, str]) -> collections.Counter:
        return collections.Counter([x])

Example of class that supports HasSpecificF:

class RImpl:
    def f(self) -> 'RImpl':
        return self

How to test

Automated tests

• utbot-python-types/src/test/kotlin/org/utbot/python/newtyping/PythonSubtypeCheckerTest.kt:
  • testSupportsCall
  • testSupportsSpecificCall

Self-check list

Check off the item if the statement is true. Hint: [x] is a marked item.

Please do not delete the list or its items.

• [ ] I've set the proper labels for my PR (at least, for category and component).
• [x] PR title and description are clear and intelligible.
• [x] I've added enough comments to my code, particularly in hard-to-understand areas.
• [x] The functionality I've repaired, changed or added is covered with automated tests.
• [ ] Manual tests have been provided optionally.
• [ ] The documentation for the functionality I've been working on is up-to-date.