code: protected ClassLoader getClassLoaderIncludingProjectClasspath() throws MojoExecutionException {
          try {
              List classpathElements = project.getCompileClasspathElements();
              classpathElements.add(project.getBuild().getOutputDirectory());
              URL urls[] = new URL[classpathElements.size()];
              for (int i = 0; i < classpathElements.size(); ++i) {
                  urls[i] = new File((String) classpathElements.get(i)).toURI().toURL();
              }
              return new URLClassLoader(urls, getMavenArtifactClassLoader());
          } catch (Exception e) {
              throw new MojoExecutionException("Failed to create project classloader", e);
          }
      }
docs: Returns an isolated classloader.
  
  @return ClassLoader
  @noinspection unchecked