Yes               251 base/bind_helpers.h   static Yes& Check(...);
Yes               254 base/bind_helpers.h   static const bool value = sizeof(Check<Base>(0)) == sizeof(Yes);
Yes               283 base/bind_helpers.h   static Yes& Check(typename U::IsMethod*);
Yes               289 base/bind_helpers.h   static const bool value = sizeof(Check<T>(0)) == sizeof(Yes);