Removes the objects in the range start inclusive to end exclusive.
The start and end indices must be in the range
0 ≤ index ≤ length, and start ≤ end.
Throws an UnsupportedError if this is a fixed-length list. In that case
the list is not modified.
Source
void removeRange(int start, int end) {
RangeError.checkValidRange(start, end, this.length);
int length = end - start;
setRange(start, this.length - length, this, end);
this.length -= length;
}