when:
        expectResourceRead(name, "12345")
        def result = resource.writeToIfPresent(file)

        then:
        result.bytesRead == 5
        file.text == "12345"
        0 * _

        when:
        expectResourceRead(name, "hi")
        result = resource.writeTo(file)

        then:
        result.bytesRead == 2