大名鼎鼎的java动态脚本语言。已经通过了sun的认证

				class OptionalReturnTest extends GroovyTestCase {									def y									    void testSingleExpression() {				        def value = foo()										        assert value == 'fooReturn'				    }								    void testLastExpressionIsSimple() {				        def value = bar()				        				        assert value == 'barReturn'				    }								    void testLastExpressionIsBooleanExpression() {				        def value = foo2()				        				        assert value								        value = foo3()				        				        assert value == false				    }								    void testLastExpressionIsAssignment() {				        def value = assign()				        				        assert value == 'assignReturn'				        				        value = assignField()				        				        assert value == 'assignFieldReturn'				    }								    void testLastExpressionIsMethodCall() {				        def value = methodCall()				        				        assert value == 'fooReturn'				    }								    void testEmptyExpression() {				        def value = nullReturn()				        				        assert value == null				    }								    //  now this is not a compile time error in jsr-03				    void testVoidMethod() {				        def value = voidMethod()								        assert value == null				    }								    void testNonAssignmentLastExpressions() {				        def value = lastIsAssert()				        				        assert value == null				    }								    def foo() {				        'fooReturn'				    }										    def bar() {				        def x = 'barReturn'				        x				    }									    def foo2() {				        def x = 'cheese'				        x == 'cheese'				    }									    def foo3() {				        def x = 'cheese'				        x == 'edam'				    }									    def assign() {				        def x = 'assignReturn'				    }									    def assignField() {				        y = 'assignFieldReturn'				    }				    				    def nullReturn() {				    }								    def lastIsAssert() {				        assert 1 == 1				    }								    def methodCall() {				        foo()				    }				    				    void voidMethod() {				        foo()				    }				}