Add @raise annotation to gem's method

Hi!

How do I tell to Rubymine that some external method throws an error?

Say I have such code:

user = User.find(id)
unless user
  invalid!() # it's a method from Tzu gem that raises an error
end

puts user.address # <-- here Rubymine says that user can be nil
# But in the reality it cannot as there would be an error earlier.