PrintStream ps = new PrintStream(os);
                ps.println("Unable to load the mojo '" + mojoDescriptor.getGoal() + "' in the plugin '"
                        + pluginDescriptor.getId() + "'. A required class is missing: "
                        + cause.getMessage());
                pluginRealm.display(ps);

                throw new PluginContainerException(mojoDescriptor, pluginRealm, os.toString(), cause);

    }

    private void printErrors(ArtifactResolutionResult result) {
        if (result.hasMissingArtifacts()) {
            for (Artifact artifact : result.getMissingArtifacts()) {
                System.err.println("Missing: " + artifact);
            }
        }

        if (result.hasExceptions()) {
            for (Exception e : result.getExceptions()) {
                e.printStackTrace();
            }
        }

                        .exists(settingsFile.getExists())
                        .missing(settingsFile.getMissing())
                        .location("exists", toLocation(settingsFile.getLocation("exists")))
                        .location("missing", toLocation(settingsFile.getLocation("missing")))
                        .build());
            }

            ByteArrayOutputStream os = new ByteArrayOutputStream(1024);
            PrintStream ps = new PrintStream(os);
            ps.println(
                    "A required class was missing while executing " + mojoDescriptor.getId() + ": " + e.getMessage());
            pluginRealm.display(ps);
            Exception wrapper = new PluginContainerException(mojoDescriptor, pluginRealm, os.toString(), e);

  a result turning off certain services provided by m2 and providing a coherent
  way of predicting and reporting when network-related failures will take place.
  It means warning users that since the network is missing, certain features and
  operations will be unavailable, rather than simply waiting for those
  operations to fail, then trying to help users decipher the error messages they
  get as a result.

    @Inject
    private ArtifactRepositoryFactory artifactRepositoryFactory;

    @Test
    void testUnnecessaryRepositoryLookup() throws Exception {
        Artifact artifact = createTestPomArtifact("target/test-data/get-missing-pom");

        List<ArtifactRepository> repos = new ArrayList<>();
        repos.add(artifactRepositoryFactory.createArtifactRepository(
                "repo1", "string://url1", new ArtifactRepositoryLayoutStub(), null, null));

            return false;
        }

        if (!string.isEmpty()) {
            return true;
        }

        addViolation(problems, BuilderProblem.Severity.ERROR, fieldName, sourceHint, "is missing");

        return false;
    }

    /**
     * Asserts:
     * <p/>
     * <ul>
     * <li><code>string != null</code>
     * </ul>
     */
    private static boolean validateNotNull(

                    missingDescriptor(session, trace, a, (Exception) e.getCause());
                    if ((getPolicy(session, a, request) & ArtifactDescriptorPolicy.IGNORE_MISSING) != 0) {
                        return null;
                    }
                }
                result.addException(e);
                throw new ArtifactDescriptorException(result);
            }

                        // 1 extra '/' to remove
                        url.setLength(url.length() - 1);
                    }
                } else if (!initialUrlEndsWithSlash) {
                    // add missing '/' between url and path
                    url.append('/');
                }

                url.append(path);

                // ensure resulting url ends with slash if initial url was