code: function setFormat(format) {
              if (format === null || format === undefined) {
                  throw new Error("Format is not defined " + this.clazz.$name);
              }
  
              if (this.format !== format) {
                  this.format = format;
                  this.$getSuper("setValue").call(this, this.$format(this.date));
              }
  
              return this;
          }
docs: Set the pattern to be used to format date
  @param {String} format a format pattern
  @method setFormat
  @chainable