code: public void execute() throws MojoExecutionException, MojoFailureException {
          try {
              removeFromResources(blocksDir);
              removeFromResources(resourcesDir);
              File targetDir = new File(outputDir);
              boolean jar = "jar".equalsIgnoreCase(mavenProject.getPackaging());
              if (jar) {
                  JarBuilder builder = new JarBuilder(blocksDir, resourcesDir, targetDir, mavenProject, mavenSession, getLog());
                  builder.generate();
              } else {
                  WarBuilder builder = new WarBuilder(blocksDir, resourcesDir, targetDir, mavenProject, mavenSession, getLog());
                  builder.generate();
              }
          } catch (Exception e) {
              throw new MojoFailureException("Source generator error", e);
          }
      }
docs: protected MojoExecutor.ExecutionEnvironment _pluginEnv;