private void makeTerrainVisible(Coordinate coord) {
// executing a change is needed only if something changes...
if (!isTerrainVisible(coord)) {
MakeTerrainVisible realChange
= new MakeTerrainVisible(coord, this);
realChange.execute();
}
}
private void makeTerrainVisible(Set<Coordinate> coords) {
Iterator<Coordinate> iterator = coords.iterator();