Used in place of a `VerifyingExistingMethodDouble` for the specific case of mocking or stubbing a `new` method on a class. In this case, we substitute the method signature from `#initialize` since new's signature is just `*args`.
@private
# File lib/rspec/mocks/verifying_proxy.rb, line 208 def with_signature yield Support::MethodSignature.new(object.instance_method(:initialize)) end