Description

Currently, there's no way to create a poll ("quiz" type) without any explanation using Client.send_poll.
When explanation parameter is not passed (explanation=None), current code stringifies None to "None".
But, when explanation=None, explanation_entities is required to be None too (explanation_entities=None), while current solution forces explanation_entities to always be a list.
This patch ensures that the required cases get handled properly, fixing the current bugs.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

I manually tested various combinations of parameters (explanation and explanation_entities) of Client.send_poll.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• My changes generate no new warnings
• New and existing unit tests pass locally with my changes