* @return The toolchains model or <code>null</code> if no toolchain file was configured or the configured file does
     *         not exist.
     * @throws MisconfiguredToolchainException If the toolchain file exists but cannot be parsed.
     */
    PersistedToolchains build(File userToolchainsFile) throws MisconfiguredToolchainException;

                    // ignore
                }
                metadataFile.delete(); // if this fails, forget about it, we'll try to overwrite it anyway so no need
                // to delete on exit
            }
        } else if (metadataFile.exists()) {
            try (InputStream input = Files.newInputStream(metadataFile.toPath())) {
                metadata = new Metadata(new MetadataStaxReader().read(input, false));
            }
        }

        Properties properties = new Properties();
        Path path = rootBuildDirectory.resolve(RESUME_PROPERTIES_FILENAME);
        if (!Files.exists(path)) {
            LOGGER.warn("The {} file does not exist. The --resume / -r feature will not work.", path);
            return properties;
        }

        try (Reader reader = Files.newBufferedReader(path)) {
            properties.load(reader);

        Map.Entry<Artifact, Path> res = session.resolveArtifact(coord);
        assertNotNull(res);
        assertNotNull(res.getValue());
        assertTrue(Files.exists(res.getValue()));

        Node node = session.collectDependencies(session.createDependencyCoordinate(coord));
        assertNotNull(node);
        assertEquals(8, node.getChildren().size());
    }

        String result;
        Path src = sourcePathProvider.get();
        if (src == null) {
            Files.deleteIfExists(target);
            result = null;
        } else if (!Files.exists(src)) {
            Files.deleteIfExists(target);
            result = "";
        } else {
            String current = sha1(src);
            String existing = sourceState.get();

  * If the wagon is bound to "file://" then:

    Retrieve the file or base-url file to be "downloaded".

    * If the file (or more usefully, the base-url file) exists, proceed.

    * If the file (or base-url file) doesn't exist, assume that this location
      is part of a file-share. Ignore the request and print a debug message
      as above.

** Control over mojos in the lifecycle

            protected ActivationFile.Builder transformActivationFile_Exists(
                    Supplier<? extends ActivationFile.Builder> creator,
                    ActivationFile.Builder builder,
                    ActivationFile target) {
                final String path = target.getExists();
                final String xformed = transformPath(path, target, "exists");

                }
            }
        }
        return plugins.values();
    }

    private PluginInfo extractPluginInfo(Artifact artifact) {
        // sanity: jar, no classifier and file exists
        if (artifact != null
                && "jar".equals(artifact.getExtension())
                && "".equals(artifact.getClassifier())
                && artifact.getPath() != null) {

        Activation activation = profile.getActivation();

        ActivationFile actFile = activation.getFile();

        if (actFile != null) {
            // check if the file exists, if it does then the profile will be active
            String fileString = actFile.getExists();

            RegexBasedInterpolator interpolator = new RegexBasedInterpolator();
            try {

        assertNull(
                updateCheckManager.readLastUpdated(touchFile, updateCheckManager.getRepositoryKey(remoteRepository)));

        assertFalse(updateCheckManager.getTouchfile(a).exists());
    }

    @Test
    void testMissingArtifact() throws Exception {
        ArtifactRepository remoteRepository = remoteRepository();

        ArtifactRepository localRepository = localRepository();