public abstract boolean removeAll (Collection<?> c)

Removes all of this collection's elements that are also contained in the specified collection (optional operation). After this call returns, this collection will contain no elements in common with the specified collection.

Parameters:
c    collection containing elements to be removed from this collection

Returns:  true if this collection changed as a result of the call

Exceptions:
UnsupportedOperationException    if the removeAll method is not supported by this collection
ClassCastException    if the types of one or more elements in this collection are incompatible with the specified collection (optional)
NullPointerException    if this collection contains one or more null elements and the specified collection does not support null elements (optional), or if the specified collection is null

See also:
remove(Object), contains(Object)