fillRange method Null safety
override
Sets the objects in the range start inclusive to end exclusive
to the given fillValue.
The provided 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.
Example:
List<int> list = new List(3);
list.fillRange(0, 2, 1);
print(list); // [1, 1, null]
If the element type is not nullable, omitting fillValue or passing null
as fillValue will make the fillRange fail.
Implementation
void fillRange(int start, int end, [E? fillValue]) {
throw new UnsupportedError("Cannot modify an immutable List.");
}