# File lib/mongoid/relations/bindings/referenced/one.rb, line 21
          def bind
            unless _binding?
              _binding do
                target.you_must(metadata.foreign_key_setter, base.id)
                target.send(metadata.inverse_setter, base)
                if metadata.type
                  target.you_must(metadata.type_setter, base.class.model_name)
                end
              end
            end
          end