* @param droneType Type of Drone, e.g. WebDriver
* @param qualifier Qualifier
* @return Returns {@code true} if this is first Drone of given type, {@code false} otherwise
*/
public boolean isUniqueInScope(Class<?> droneType, Class<? extends Annotation> qualifier) {
QualifiedKey key = new QualifiedKey(droneType, qualifier);
// put qualified key there and return whether it was the first key
return presentDrones.add(key);
}