public void assertFileExistence(File dir, String filename, boolean shouldExist) {
        File file = new File(dir, filename);

        if (shouldExist) {
            assertTrue(file.exists());
        } else {
            assertFalse(file.exists());
        }
    }

    public void assertFileContents(File dir, String filename, String contentsTest, String encoding) throws IOException {

        // No project, but most certainly a dependency which has been built previously
        File packagedArtifactFile = findInProjectLocalRepository(artifact);
        if (packagedArtifactFile != null && packagedArtifactFile.exists()) {
            return packagedArtifactFile;
        }

        return null;
    }

    public List<String> findVersions(Artifact artifact) {
        List<String> versions = getProjects()

        assertFalse(file.exists(), "Remote artifact " + file + " should not be present.");
    }

    protected void assertLocalArtifactNotPresent(Artifact artifact) throws Exception {
        ArtifactRepository localRepo = localRepository();

        String path = localRepo.pathOf(artifact);

        File file = new File(localRepo.getBasedir(), path);

            File deployedFile = new File(remoteRepository.getBasedir(), remoteRepository.pathOf(artifact));
            assertTrue(deployedFile.exists());
            assertEquals("dummy", new String(Files.readAllBytes(deployedFile.toPath()), StandardCharsets.UTF_8).trim());
        } finally {
            sessionScope.exit();
        }
    }

                    // 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));
            }
        }

        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());
    }

  @J2ktIncompatible // serialization
  Object writeReplace() {
    return new SerializedForm<E>(comparator, toArray());
  }

  /**
   * Not supported. Use {@link #toImmutableSortedSet} instead. This method exists only to hide
   * {@link ImmutableSet#toImmutableSet} from consumers of {@code ImmutableSortedSet}.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Use {@link ImmutableSortedSet#toImmutableSortedSet}.

    public static final String CURRENT_ACCESSORS_OF_UPGRADED_PROPERTIES = "currentAccessorsOfUpgradedProperties";

    public static List<UpgradedProperty> parse(String path) {
        File file = new File(path);
        if (!file.exists()) {
            return Collections.emptyList();
        }
        try {
            return new Gson().fromJson(new FileReader(file), new TypeToken<List<UpgradedProperty>>() {}.getType());

                }
            }
        }
        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) {

        File localFile = new File(localRepo.getBasedir(), localRepo.pathOf(artifact));

        artifact.setFile(localFile);

        if (!localFile.exists()) {
            if (request.getRemoteRepositories().isEmpty()) {
                throw new IOException(localFile + " does not exist and no remote repositories are configured");
            }

            ArtifactRepository remoteRepo = request.getRemoteRepositories().get(0);