public void setReturnType(FullyQualifiedJavaType returnType) {
        this.returnType = returnType;
    }
@Test
    void testSetReturnType() {
        Method method = new Method("bar");
        assertFalse(method.getReturnType().isPresent());

        method.setReturnType(FullyQualifiedJavaType.getIntInstance());
        assertEquals(FullyQualifiedJavaType.getIntInstance(), method.getReturnType().get());
    }