code: function(items, connector) {
              var length = items.length,
                  head,
                  tail;
  
              if (length <= 1) {
                  return items[0];
              } else {
                  head = items.slice(0, length - 1);
                  tail = items[length - 1];
  
                  return Ext.util.Format.format("{0} {1} {2}", head.join(", "), connector || 'and', tail);
              }
          }
docs: Turns an array into a sentence, joined by a specified connector - e.g.:
  
  Ext.toSentence(['Adama', 'Tigh', 'Roslin']); //'Adama, Tigh and Roslin'
  Ext.toSentence(['Adama', 'Tigh', 'Roslin'], 'or'); //'Adama, Tigh or Roslin'
  
  @param {String[]} items The array to create a sentence from
  @param {String} connector The string to use to connect the last two words.
  Usually 'and' or 'or' - defaults to 'and'.
  @return {String} The sentence string
  @deprecated 4.0.0 Will be removed in the next major version