* a model source such as a string or input stream.
     *
     * @return an optional containing the source of the project, or empty if not specified
     */
    @Nonnull
    Optional<Source> getSource();

    /**
     * Determines whether a stub model should be allowed when the POM is missing or unreadable.
     * A stub model contains only minimal information derived from the project's coordinates.
     *

   * Returns the object that originated this event (not the object that originated the
   * wrapped event). This is generally an {@link EventBus}.
   *
   * @return the source of this event.
   */
  public Object getSource() {
    return source;
  }

  /**
   * Returns the wrapped, 'dead' event, which the system was unable to deliver to any registered
   * subscriber.
   *
   * @return the 'dead' event that could not be delivered.

            indent.append("  ");

            InputLocation location = plugin.getLocation("");
            if (location != null && location.getSource() != null) {
                trackingData.add(indent + location.getSource().getModelId() + " (implicit)");
                indent.append("  ");
            }
        } else if (collectStepTrace != null) {

        this.setComponents(clone(original.getMojos(), this));
        this.setId(original.getId());
        this.setIsolatedRealm(original.isIsolatedRealm());
        this.setSource(original.getSource());
        this.setDependencies(original.getDependencies());
        this.setDependencyNode(original.getDependencyNode());
    }

                                        .failure("%sConfiguration validation of %s: %s")
                                        .build(),
                        indent,
                        response.getSource(),
                        response.isValid() ? "VALID" : "INVALID")
                .build());
        for (Map.Entry<SecDispatcher.ValidationResponse.Level, List<String>> entry :

    super(message);
    this.conflicts = conflicts;
    this.source = source;
  }

  public Set<Feature<?>> getConflicts() {
    return conflicts;
  }

  public Object getSource() {
    return source;
  }

  @Override
  public String getMessage() {
    return super.getMessage() + " (source: " + source + ")";
  }

                    String projectId = extractProjectId(r);
                    File sourcePomFile = r.getSource() != null && r.getSource().getPath() != null
                            ? r.getSource().getPath().toFile()
                            : null;
                    results.add(new DefaultProjectBuildingResult(

        }

        @Override
        public ModelData intoCache(ModelData data) {
            Model model = (data.getModel() != null) ? data.getModel().clone() : null;
            return new ModelData(data.getSource(), model, data.getGroupId(), data.getArtifactId(), data.getVersion());
        }

        @Override
        public ModelData fromCache(ModelData data) {
            return intoCache(data);
        }
    };

            }
        }
        assertNotNull(dependencyLocation, "missing dependency");
        assertEquals(
                "org.apache.maven.its:bom:0.1", dependencyLocation.getSource().getModelId());

        InputLocation pluginLocation = null;
        for (Plugin plugin : project.getBuildPlugins()) {
            if (plugin.getKey().equals("org.apache.maven.plugins:maven-clean-plugin")) {

                .map(MojoExecution::getPlugin)
                .filter(p -> p.getLocation("version") != null
                        && p.getLocation("version").getSource() != null
                        && defaulModelId.equals(
                                p.getLocation("version").getSource().getModelId()))
                .distinct()
                .map(Plugin::getArtifactId) // managed by us, groupId is always o.a.m.plugins