code: function(fromClass, members) {
              //<debug>
              Ext.classSystemMonitor && Ext.classSystemMonitor(this, 'Ext.Base#borrow', arguments);
              //</debug>
              
              var prototype = this.prototype,
                  fromPrototype = fromClass.prototype,
                  //<debug>
                  className = Ext.getClassName(this),
                  //</debug>
                  i, ln, name, fn, toBorrow;
  
              members = Ext.Array.from(members);
  
              for (i = 0,ln = members.length; i < ln; i++) {
                  name = members[i];
  
                  toBorrow = fromPrototype[name];
  
                  if (typeof toBorrow == 'function') {
                      fn = Ext.Function.clone(toBorrow);
  
                      //<debug>
                      if (className) {
                          fn.displayName = className + '#' + name;
                      }
                      //</debug>
  
                      fn.$owner = this;
                      fn.$name = name;
  
                      prototype[name] = fn;
                  }
                  else {
                      prototype[name] = toBorrow;
                  }
              }
  
              return this;
          }
docs: Borrow another class' members to the prototype of this class.
  
  Ext.define('Bank', {
  money: '$$$',
  printMoney: function() {
  alert('$$$$$$$');
  }
  });
  
  Ext.define('Thief', {
  ...
  });
  
  Thief.borrow(Bank, ['money', 'printMoney']);
  
  var steve = new Thief();
  
  alert(steve.money); // alerts '$$$'
  steve.printMoney(); // alerts '$$$$$$$'
  
  @param {Ext.Base} fromClass The class to borrow members from
  @param {Array/String} members The names of the members to borrow
  @return {Ext.Base} this
  @static
  @inheritable
  @private