BUG - when the object is accessed (type-cast) affects the patch

[shobnaren]

print(list(result)) ## typecast change causes the breakage
patched = patch(result,first)
assert patched == second

This fails when there is print(list(result)) but works fine when there is no print/type-cast involved.

[holvi-mikael]

result is a generator, which you exhaust when feeding it to the list (list() is a regular constructor, not "typecasting", which does not really exist in Python outside low-level C interop).
If you want to view the result via list before using it, store the resulting list and use that instead when patching.