code: protected void execute(CommandLine cmdLine)
              throws MojoFailureException, MojoExecutionException
          {
          try
              {
              DefaultExecutor executor = new DefaultExecutor();
              executor.setWorkingDirectory(workingDir);
              executor.setStreamHandler(new PumpStreamHandler(System.out, System.err, System.in));
  
              executor.execute(cmdLine);
              }
          catch (ExecuteException e)
              {
              throw new MojoFailureException("npm failure", e);
              }
          catch (IOException e)
              {
              throw new MojoExecutionException("Error executing NPM", e);
              }
          }
docs: ---- helpers ---------------------------------------------------------