--XXX public class XXXXXXXXXXXX and the public class Fleet are XXXXXXXXXX XX Composition (black XXXXXXX). Again, XXXXXXXXXXXX XXXX XXXXXX. Think XX it like this, XXXXXXXXXXXX owns --&XX; Fleets XXXX --&XX; Vehicles. XXXX XXX XXXXX XXXXXXX must XX XX the XXXXXXXXXXXX side
--Now, XXX multiplicity for Composition between public XXXXX XXXXXXXXXXXX XXX public class Fleet looks XX be: "X" for FleetManager side (Fleet must be XXXXXXXXXX with exactly 1 FleetManager, can't have an unmanaged XXXXX) and "X..*" (XXXXXXXXXXXX can XX XXXXXXXXXX with 0 or more fleets).