/**
* Returns an array containing all of the elements in this set; the runtime type of the returned
* array is that of the specified array. If the set fits in the specified array, it is returned
* therein. Otherwise, a new array is allocated with the runtime type of the specified array and
* the size of this set.
*
* <p>If this set fits in the specified array with room to spare (i.e., the array has more
* elements than this set), the element in the array immediately following the end of the set is
* set to <tt>null</tt>. (This is useful in determining the length of this set <i>only</i> if the
* caller knows that this set does not contain any null elements.)
*
* <p>If this set makes any guarantees as to what order its elements are returned by its iterator,
* this method must return the elements in the same order.
*
* <p>Like the {@link #toArray()} method, this method acts as bridge between array-based and
* collection-based APIs. Further, this method allows precise control over the runtime type of the
* output array, and may, under certain circumstances, be used to save allocation costs.
*
* <p>Suppose <tt>x</tt> is a set known to contain only strings. The following code can be used to
* dump the set into a newly allocated array of <tt>String</tt>:
*
* <pre>
* String[] y = x.toArray(new String[0]);
* </pre>
*
* Note that <tt>toArray(new Object[0])</tt> is identical in function to <tt>toArray()</tt>.
*
* @param a the array into which the elements of this set are to be stored, if it is big enough;
* otherwise, a new array of the same runtime type is allocated for this purpose.
* @return an array containing all the elements in this set
* @throws ArrayStoreException if the runtime type of the specified array is not a supertype of
* the runtime type of every element in this set
* @throws NullPointerException if the specified array is null
*/
public <T> T[] toArray(T[] a) {
return al.toArray(a);
}
/**
* Returns an array containing all of the elements in this set. If this set makes any guarantees
* as to what order its elements are returned by its iterator, this method must return the
* elements in the same order.
*
* <p>The returned array will be "safe" in that no references to it are maintained by this set.
* (In other words, this method must allocate a new array even if this set is backed by an array).
* The caller is thus free to modify the returned array.
*
* <p>This method acts as bridge between array-based and collection-based APIs.
*
* @return an array containing all the elements in this set
*/
public Object[] toArray() {
return al.toArray();
}