code: function () {
                      var key, value;
                      if ((key = $(/^\w+(?=\s?=)/i)) && $('=') && (value = $(this.entity))) {
                          return new(tree.Assignment)(key, value);
                      }
                  }
docs: Assignments are argument entities for calls. They are present in ie filter properties as shown below.  filter: progid:DXImageTransform.Microsoft.Alpha( *opacity=50* )