code: function(value1, value2){
          return String(Ext.value(value1, '')) === String(Ext.value(value2, ''));
      }
docs: Returns whether two values are logically equal.
  Similar to {@link #isEqual}, however null or undefined values will be treated as empty strings.
  @private
  @param {Object} value1 The first value to compare
  @param {Object} value2 The second value to compare
  @return {Boolean} True if the values are equal, false if inequal.