code: def pop_viewport(self):
          
          vp = self._vp_stack.pop()
          # Activate latest
          if len(self._vp_stack) > 0:
              self.context.set_viewport(*self._vp_stack[-1])
          else:
              self.context.set_viewport(0, 0, *self.physical_size)
          
          self._update_transforms()
          return vp
docs: Pop a viewport from the stack.