code: private ExceptionCollection collectDependencyManagementDependencies(ProjectBuildingRequest buildingRequest, MavenProject project,
              List<DependencyNode> nodes, boolean aggregate) {
          if (skipDependencyManagement || project.getDependencyManagement() == null) {
              return null;
          }
  
          ExceptionCollection exCol = null;
          for (org.apache.maven.model.Dependency dependency : project.getDependencyManagement().getDependencies()) {
              try {
                  nodes.add(toDependencyNode(buildingRequest, null, dependency));
              } catch (ArtifactResolverException ex) {
                  getLog().debug(String.format("Aggregate : %s", aggregate));
                  if (exCol == null) {
                      exCol = new ExceptionCollection();
                  }
                  exCol.addException(ex);
              }
          }
          return exCol;
      }
docs: Collect dependencies from the dependency management section.
  
  @param buildingRequest the Maven project building request
  @param project the project being analyzed
  @param nodes the list of dependency nodes
  @param aggregate whether or not this is an aggregate analysis
  @return a collection of exceptions if any occurred; otherwise
  <code>null</code>