[WIP] Better support for spying and stubbing on class methods

[epgui]

Changes:

• List all changes here

Rationale & Considerations

Provide a rationale for the changes. Are there any tradeoffs that were
considered?

Checklist / Reminders

• Tests have been added and give confidence that the code is working.

[codecov]

Codecov Report

Merging #6 (4d7fa66) into main (8dac1e3) will decrease coverage by 1.98%.
The diff coverage is 92.98%.

@@            Coverage Diff             @@
##             main       #6      +/-   ##
==========================================
- Coverage   99.33%   97.35%   -1.98%     
==========================================
  Files           6        7       +1     
  Lines         150      189      +39     
==========================================
+ Hits          149      184      +35     
- Misses          1        5       +4     

Impacted Files	Coverage Δ
pybond/checks.py	90.32% <90.32%> (ø)
pybond/james.py	98.50% <93.75%> (-1.50%)	⬇️
pybond/types.py	100.00% <100.00%> (ø)
pybond/util.py	97.56% <100.00%> (+0.41%)	⬆️