docs: private static MethodRef getSetOrAddMethod(FieldDescriptor descriptor) {
      TypeInfo builder = builderRuntimeType(descriptor.getContainingType());
      String prefix = descriptor.isRepeated() ? "add" : "set";
      boolean isProto3EnumField = isProto3EnumField(descriptor);
      String suffix = isProto3EnumField ? "Value" : "";
      return MethodRef.createInstanceMethod(
              builder,
              new Method(
                  prefix + getFieldName(descriptor, true) + suffix,
                  builder.type(),
                  new Type[] {isProto3EnumField ? Type.INT_TYPE : getRuntimeType(descriptor)}))
          .asNonNullable();
    }