Set < E > function ( ) { return Sets . newSetFromMap ( new IdentityHashMap < E , Boolean > ( ) ) ; }
creates an empty set that uses identity to determine equality . itcompares object references , instead of calling equals , to determine whether a provided object matches an element in the set . for example , contains returns false when passed an object thatequals a set member , but is n't the same instance . this behavior is similar to the way identityhashmap handles key lookups . concode_field_sep PlaceHolder placeHolder concode_field_sep HashSet<E> newHashSet concode_elem_sep HashSet<E> newHashSet concode_elem_sep HashSet<E> newHashSet concode_elem_sep HashSet<E> newHashSet concode_elem_sep HashSet<E> newHashSetWithCapacity concode_elem_sep Set<E> newSetFromMap concode_elem_sep LinkedHashSet<E> newLinkedHashSet concode_elem_sep CopyOnWriteArraySet<E> newCopyOnWriteArraySet