* The root interface in the <i>collection hierarchy</i>. A collection * represents a group of objects, known as its <i>elements</i>. Some * collections allow duplicate elements and others do not. Some are ordered * and others unordered. The JDK does not provide any <i>direct</i> * implementations of this interface: it provides implementations of more * specific subinterfaces like <tt>Set</tt> and <tt>List</tt>. This interface * is typically used to pass collections around and manipulate them where * maximum generality is desired.
* This class consists exclusively of static methods that operate on or return * collections. It contains polymorphic algorithms that operate on * collections, "wrappers", which return a new collection backed by a * specified collection, and a few other odds and ends.