Sole constructor. (For invocation by subclass constructors, typically implicit.)
Compares the specified object with this set for equality. Returns <tt>true</tt> if the given object is also a set, the two sets have the same size, and every member of the given set is contained in this set. This ensures that the <tt>equals</tt> method works properly across different implementations of the <tt>Set</tt> interface.<p>
Removes from this set all of its elements that are contained in the specified collection (optional operation). If the specified collection is also a set, this operation effectively modifies this set so that its value is the <i>asymmetric set difference</i> of the two sets.
Returns the hash code value for this set. The hash code of a set is defined to be the sum of the hash codes of the elements in the set, where the hash code of a <tt>null</tt> element is defined to be zero. This ensures that <tt>s1.equals(s2)</tt> implies that <tt>s1.toHash()==s2.toHash()</tt> for any two sets <tt>s1</tt> and <tt>s2</tt>, as required by the general contract of {@link Object#hashCode}.
This class provides a skeletal implementation of the <tt>Set</tt> interface to minimize the effort required to implement this interface. <p>
The process of implementing a set by extending this class is identical to that of implementing a Collection by extending AbstractCollection, except that all of the methods and constructors in subclasses of this class must obey the additional constraints imposed by the <tt>Set</tt> interface (for instance, the add method must not permit addition of multiple instances of an object to a set).<p>
Note that this class does not override any of the implementations from the <tt>AbstractCollection</tt> class. It merely adds implementations for <tt>equals</tt> and <tt>hashCode</tt>.<p>
This class is a member of the <a href="{@docRoot}/../technotes/guides/collections/index.html"> Java Collections Framework</a>.
@param !(E) the type of elements maintained by this set
@see Collection @see AbstractCollection @see Set