docs: function getBulkNpmData(pkgs, collection, npmClient, callback) {
    var next, results;
  
    results = [];
    next    = after(pkgs.length, function(err) {
      return callback(err, results);
    });
  
    pkgs.forEach(function(pkg) {
      // make sure not to make unnecessary queries to the registry
      if (isDuplicate(collection[pkg.name], pkg.version)) {
        return next(null);
      }
  
      getNpmData(pkg, npmClient, errTo(callback, function(found) {
        if (found) { results.push(found); }
  
        next(null, results);
      }));
    });
  }