removeAt method Null safety
- int pos
override
Removes the object at position index from this list.
This method reduces the length of this by one and moves all later objects
down by one position.
Returns the removed value.
The index must be in the range 0 ≤ index < length.
The list must be growable.
Implementation
E removeAt(int pos) {
throw new UnsupportedError("Cannot remove from immutable List.");
}