Ditto.

For most Ruby operations, the object type is irrelevant.  Some operations do check types (e.g. mutating ActiveRecord associations), but those should be their own expectations:

```ruby
  it "can be used in Widget#institutions" do
    institution = @pregnancy_visit_extractor.process_ # ...
    widget.institutions << institution
   
    institutions.length.should == 1
  end
```