void removeRange(int start, int end)

Removes the objects in the range start inclusive to end exclusive.

The provide range, given by start and end, must be valid. A range from start to end is valid if 0 <= start <= end <= len, where len is this list's length. The range starts at start and has length end - start. An empty range (with end == start) is valid.

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) {
  throw new UnsupportedError("Cannot removeRange on immutable List.");
}