See comment for start_segment as we continue to work around limitations of the current tracer in this method.

Events do not always finish in the order they are started for this subscriber. The traced_method_stack expects that frames are popped off in the order that they are pushed, otherwise it will continue to pop up the stack until it finds the frame it expects. This will be fixed when we replace the tracer internals, but for now we need to work around this limitation.