docs: function readCerts(paths, done) {
      if (!(paths instanceof Array))
          throw new TypeError("readCertsSync expects Array argument");
  
      async.map(paths, fs.readFile, function(err, files) {
          var opts = {};
  
          if (err) done(err);
          else switch (files.length) {
              case 1:
                  opts.pfx = files[0];
                  break;
              case 2:
                  opts.cert = files[0];
                  opts.key = files[1];
                  break;
              default:
                  opts.cert = files[0];
                  opts.key = files[1];
                  opts.ca = files.slice(2);
          }
  
          done(null, opts);
      });
  }