[BUG] Incorrect update of kwargs in Context class constructor

[dannymeijer]

Describe the bug

The __init__ method of the Context class incorrectly updates kwargs with the result of kwargs.update(arg.to_dict()), which returns None. This means that calls to Context containing another Context object, will fail.

Steps to Reproduce

1. Go to 'context.py'
2. Locate the __init__ method of the Context class
3. Observe the line kwargs = kwargs.update(arg.to_dict())
4. See the error

Expected behavior

The kwargs should be updated correctly without assigning the result of kwargs.update(arg.to_dict()) to kwargs.