addObserver method
Register an observer of the cell to be called when the cell's value changes.
Implementation
@override
void addObserver(CellObserver observer) {
// Do nothing since the value of the cell never changes
}
Register an observer of the cell to be called when the cell's value changes.
@override
void addObserver(CellObserver observer) {
// Do nothing since the value of the cell never changes
}