)
Adds the next chunk to this.
Adds the substring defined by start and end-exclusive to this.
If isLast is true closes this.
Source
/**
* Adds the next [chunk] to `this`.
*
* Adds the substring defined by [start] and [end]-exclusive to `this`.
*
* If [isLast] is `true` closes `this`.
*/
void addSlice(String chunk, int start, int end, bool isLast);