code: function(done, packageAll) {
  
        // Detect any new file or modified files.
        var metadataAction = force.evaluateProjectFiles(opt, packageAll);
  
        // Clear the meta data output directory.
        force.deletePackageOutput(opt, false);
  
        // Check to see if any file changes were detected.
        if (Object.keys(metadataAction).length == 0) {
          // Silently return without an error when forcePackageContinueSilent is true
          if (opt.forcePackageContinueSilent) {
            done();
            return;
          }
  
          var msg = 'No new or modified files detected.';
  
          // Throw a gulp error to note no file changes detected.
          if (gutil !== undefined && gutil !== null)
            throw new gutil.PluginError(gulpPluginName, msg, { showProperties: false, showStack: false });
  
          // Return an error to gulp.
          console.log(msg);
          done(msg);
  
          return;
        }
  
        // Generate package folder structure.
        force.generatePackageStructure(opt, metadataAction);
  
        done();
  
      }
docs: ------------------------------------------- Generate a zip package with all or changed files.