docs: private static Iterable<ParameterSpec> parameters(Iterable<Parameter> parameters) {
      ImmutableList.Builder<ParameterSpec> builder = ImmutableList.builder();
      for (Parameter parameter : parameters) {
        ParameterSpec.Builder parameterBuilder =
            ParameterSpec.builder(TypeName.get(parameter.type()), parameter.name());
        for (AnnotationMirror annotation :
            Iterables.concat(parameter.nullable().asSet(), parameter.key().qualifier().asSet())) {
          parameterBuilder.addAnnotation(AnnotationSpec.get(annotation));
        }
        builder.add(parameterBuilder.build());
      }
      return builder.build();
    }