code: private boolean usesCeylonRepo(final MavenProject project) {
          for (Repository repo : project.getRepositories()) {
              if ("ceylon".equals(repo.getLayout())) {
                  return true;
              }
          }
          
          for (Artifact ext : project.getPluginArtifacts()) {
              if (ext.getArtifactId().startsWith("ceylon")) {
                  return true;
              }
          }
          return false;
      }
docs: Checks that a project use the Ceylon Maven plugin.
  @param project Project
  @return true if the Ceylon plugin is used, false if not used