}
     }

    /**
     * Asserts that the given service is defined in this jar file.
     */
    def hasService(String serviceName, String serviceImpl) {
        assertFilePresent("META-INF/services/$serviceName", serviceImpl)
    }

    /**
     * Asserts that the manifest file is present and first entry in this jar file.
     */
    void assertManifestPresentAndFirstEntry() {

        assertThat(content(relativePath), contentMatcher)
        this
    }

    /**
     * Asserts that there is a file present with the given path and content.
     */
    def assertFilePresent(String relativePath, String fileContent) {
        assertThat(filesByRelativePath.get(relativePath), hasItem(fileContent))
        this
    }