code: public ModifierAdjustment withMethodModifiers(ElementMatcher<? super MethodDescription> matcher,
                                                    List<? extends ModifierContributor.ForMethod> modifierContributors) {
          return withInvokableModifiers(isMethod().and(matcher), modifierContributors);
      }
docs: Adjusts a method's modifiers if it fulfills the supplied matcher.
  
  @param matcher              The matcher that determines if a method's modifiers should be adjusted.
  @param modifierContributors The modifier contributors to enforce.
  @return A new modifier adjustment that enforces the given modifier contributors and any previous adjustments.