Collection extends Object

Properties
`Integer`	`size`
	returns the size of this Collection
`Boolean`	`isEmpty`
	returns true if this Collection is empty

Operations
`Collection[Object]`	`remove(Object)`
	removes the specified element from this Collection if contained (modifies it!). returns this Collection.
`Set[Object]`	`toSet()`
	converts this collection to Set
`List[Object]`	`toList()`
	converts this collection to List
`Boolean`	`containsAll(Collection[Object])`
	returns true if this collection contains each element contained in the specified collection. otherwise false. returns this Collection.
`Collection[Object]`	`removeAll(Object)`
	removes all elements contained in the specified collection from this Collection if contained (modifies it!). returns this Collection.
`Collection[Object]`	`addAll(Collection[Object])`
	adds all elements to the Collection (modifies it!). returns this Collection.
`String`	`toString(String)`
	concatenates each contained element (using toString()), separated by the specified String.
`Boolean`	`contains(Object)`
	returns true if this collection contains the specified object. otherwise false. returns this Collection.
`Set[Object]`	`intersect(Collection[Object])`
	returns a new Set, containing only the elements contained in this and the specified Collection
`Set[Object]`	`without(Collection[Object])`
	returns a new Set, containing all elements from this Collection without the elements from specified Collection
`List[Object]`	`flatten()`
	returns a flatten List.
`Set[Object]`	`union(Collection[Object])`
	returns a new Set, containing all elements from this and the specified Collection
`Collection[Object]`	`add(Object)`
	adds an element to the Collection (modifies it!). returns this Collection.