# File lib/rspec/mocks/syntax.rb, line 25
      def self.enable_should(syntax_host = default_should_syntax_host)
        return if should_enabled?(syntax_host)

        syntax_host.class_eval do
          def should_receive(message, opts={}, &block)
            opts[:expected_from] ||= caller(1)[0]
            ::RSpec::Mocks.expect_message(self, message.to_sym, opts, &block)
          end

          def should_not_receive(message, &block)
            opts = {:expected_from => caller(1)[0]}
            ::RSpec::Mocks.expect_message(self, message.to_sym, opts, &block).never
          end

          def stub(message_or_hash, opts={}, &block)
            ::RSpec::Mocks::Syntax.stub_object(self, message_or_hash, opts, &block)
          end

          def unstub(message)
            ::RSpec::Mocks.space.proxy_for(self).remove_stub(message)
          end

          def stub!(message_or_hash, opts={}, &block)
            ::RSpec.deprecate "stub!", :replacement => "stub"
            ::RSpec::Mocks::Syntax.stub_object(self, message_or_hash, opts, &block)
          end

          def unstub!(message)
            ::RSpec.deprecate "unstub!", :replacement => "unstub"
            unstub(message)
          end

          def stub_chain(*chain, &blk)
            ::RSpec::Mocks::StubChain.stub_chain_on(self, *chain, &blk)
          end

          def as_null_object
            @_null_object = true
            ::RSpec::Mocks.proxy_for(self).as_null_object
          end

          def null_object?
            defined?(@_null_object)
          end

          def received_message?(message, *args, &block)
            ::RSpec::Mocks.proxy_for(self).received_message?(message, *args, &block)
          end

          unless Class.respond_to? :any_instance
            Class.class_eval do
              def any_instance
                ::RSpec::Mocks.any_instance_recorder_for(self)
              end
            end
          end
        end
      end