code: def apply_parameters(self, parameters):
          
          self.recipe.apply_parameters(parameters)
          self.recipe_step = self.recipe[self.recipe_pointer]
docs: Recursively apply parameter replacement (see recipe.py) to the wrapped
          recipe, updating internal references afterwards.
          While this operation is useful for testing it should not be used in
          production. Replacing parameters means that the recipe changes as it is
          passed down the chain of services. This makes debugging very difficult.