code: function pluginFlags(plugins) {
    var pflags = [];
    var len = 0;
  
    plugins.forEach(function(plugin) {
      Object.keys(plugin.flags || {}).forEach(function(flag) {
        pflags.push([flag, plugin.flags[flag]]);
        len = Math.max(flag.length, len);
      });
    });
  
    if (pflags.length) {
      console.log();
      console.log('Plugin flags:');
      console.log();
      pflags.forEach(function(flag) {
        console.log('  %s   %s', ljust(flag[0], len), flag[1]);
      });
    }
  
    console.log();
  }
docs: Print CLI flags from plugins.
  
  @param {Array} plugins
  @api private