code: function ( begin_prop, finish_prop ) {
          var findIdx = this._propertyIndexOf( finish_prop.name ),
              styleName = $B.string.camelCase( finish_prop.name );
  
          begin_prop.styleName = styleName;
          finish_prop.styleName = styleName;
  
          if ( findIdx == -1 ) {
              this._b_props.push( begin_prop );
              this._f_props.push( finish_prop );
          } else {
              this._b_props[findIdx] = begin_prop;
              this._f_props[findIdx] = finish_prop;
          }
  
          this._propLength = this._f_props.length;
      }
docs: 스타일속성 배열에 넣기