class T::Enum

def self.serialize(instance)
  # This is needed otherwise if a Chalk::ODM::Document with a property of the shape
  # T::Hash[T.nilable(MyEnum), Integer] and a value that looks like {nil => 0} is
  # serialized, we throw the error on L102.
  return nil if instance.nil?
  if self == T::Enum
    raise "Cannot call T::Enum.serialize directly. You must call on a specific child class."
  end
  if instance.class != self
    raise "Cannot call #serialize on a value that is not an instance of #{self}."
  end
  instance.serialize
end