Package Summary Overview Summary

### method:contains(java.lang.Object) [CHANGED]
### contains public boolean contains (Object o) Returns `true` if this setcollection contains the specified element. More formally, returns `true` if and only if this setcollection contains anat least one element `e` such that `Objects.equals(o, e)` . Specified by: `contains` in interface `Collection<K>` Specified by: `contains` in interface `Set<K>` Parameters: `o` - element whose presence in this setcollection is to be tested Returns: `true` if this setcollection contains the specified element Throws: `NullPointerException` - if the specified key is null
### contains public boolean contains (Object o) Returns `true` if this set contains the specified element. More formally, returns `true` if and only if this set contains an element `e` such that `Objects.equals(o, e)` . Specified by: `contains` in interface `Collection<K>` Specified by: `contains` in interface `Set<K>` Parameters: `o` - element whose presence in this set is to be tested Returns: `true` if this set contains the specified element Throws: `NullPointerException` - if the specified key is null | ### contains public boolean contains (Object o) Returns `true` if this collection contains the specified element. More formally, returns `true` if and only if this collection contains at least one element `e` such that `Objects.equals(o, e)` . Specified by: `contains` in interface `Collection<K>` Specified by: `contains` in interface `Set<K>` Parameters: `o` - element whose presence in this collection is to be tested Returns: `true` if this collection contains the specified element Throws: `NullPointerException` - if the specified key is null

### method:iterator() [CHANGED]
### iterator public Iterator<K> iterator() Description copied from interface: `Set` Returns an iterator over the elements in this setcollection. The elements arereturned in no particular order (unless this setiterator is an instance of some class that provides a guarantee)weakly consistent . Specified by: `iterator` in interface `Collection<K>` Specified by: `iterator` in interface `Iterable<K>` Specified by: `iterator` in interface `Set<K>` Returns: an iterator over the keys of the backing map
### iterator public Iterator<K> iterator() Description copied from interface: `Set` Returns an iterator over the elements in this set. The elements are returned in no particular order (unless this set is an instance of some class that provides a guarantee). Specified by: `iterator` in interface `Collection<K>` Specified by: `iterator` in interface `Iterable<K>` Specified by: `iterator` in interface `Set<K>` Returns: an iterator over the keys of the backing map | ### iterator public Iterator<K> iterator() Returns an iterator over the elements in this collection. The returned iterator is weakly consistent . Specified by: `iterator` in interface `Collection<K>` Specified by: `iterator` in interface `Iterable<K>` Specified by: `iterator` in interface `Set<K>` Returns: an iterator over the keys of the backing map

### method:hashCode() [CHANGED]
### hashCode public int hashCode() Description copied from interfaceclass: `SetObject` Returns thea hash code value for the object. This method is supported for this setthe benefit of hash tables such as those provided by `HashMap`. The hash codegeneral contract of `a sethashCode` is: Whenever it is defined to beinvoked on the sumsame object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the hash codesobject is modified. This integer need not remain consistent from one execution of an application to another execution of the elements insame application. If two objects are equal according to the `set, whereequals` method, then calling the `hash codehashCode` method on each of a `null` elementthe two objects must produce the same integer result. It is definednot required that if two objects are unequal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be zero. This ensuresaware that `s1.equals(s2)` implies that `s1.hashCode()==s2.hashCode()`producing distinct integer results for any two sets `s1` and `s2`, as required byunequal objects may improve the general contractperformance of `Object.hashCode()`hash tables. Specified by: `hashCode` in interface `Collection<K>` Specified by: `hashCode` in interface `Set<K>` Overrides: `hashCode` in class `Object` Returns: thea hash code value for this setobject. See Also: `Object.equals(java.lang.Object)` `Set.equals(System.identityHashCode(java.lang.Object)`
### hashCode public int hashCode() Description copied from interface: `Set` 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 `null` element is defined to be zero. This ensures that `s1.equals(s2)` implies that `s1.hashCode()==s2.hashCode()` for any two sets `s1` and `s2`, as required by the general contract of `Object.hashCode()`. Specified by: `hashCode` in interface `Collection<K>` Specified by: `hashCode` in interface `Set<K>` Overrides: `hashCode` in class `Object` Returns: the hash code value for this set See Also: `Object.equals(Object)` `Set.equals(Object)` | ### hashCode public int hashCode() Description copied from class: `Object` Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by `HashMap`. The general contract of `hashCode` is: Whenever it is invoked on the same object more than once during an execution of a Java application, the `hashCode` method must consistently return the same integer, provided no information used in `equals` comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application. If two objects are equal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce the same integer result. It is not required that if two objects are unequal according to the `equals` method, then calling the `hashCode` method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables. Specified by: `hashCode` in interface `Collection<K>` Specified by: `hashCode` in interface `Set<K>` Overrides: `hashCode` in class `Object` Returns: a hash code value for this object. See Also: `Object.equals(java.lang.Object)` `System.identityHashCode(java.lang.Object)`

### method:equals(java.lang.Object) [CHANGED]
### equals public boolean equals (Object o) Description copied from interfaceclass: ``Set`Compares the specifiedObject` Indicates whether some other object withis "equal to" this setone. The `equals` method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value `x`, `x.equals(x)` should return `true`. It is symmetric: for equality. Returnsany non-null reference values `x` and `y`, `x.equals(y)` should return `true` if and only if `the specified objecty.equals(x)` returns `true`. It is also a set, the two sets have the same sizetransitive : for any non-null reference values `x`, `y`, and `z`, if `x.equals(y)` returns `true` and `every membery.equals(z)` returns `true`, then `x.equals(z)` should return `true`. It is consistent: for any non-null reference values `x` and `y`, multiple invocations of `x.equals(y)` consistently return `true` or consistently return `false`, provided no information used in `equals` comparisons on the specified setobjects is contained in this set (or equivalently, every member of this set is contained inmodified. For any non-null reference value `x`, `x.equals(null)` should return `false`. An equivalence relation partitions the specified set). This definition ensures thatelements it operates on into equivalence classes ; all the equals method works properly across different implementationsmembers of an equivalence class are equal to each other. Members of the set interfacean equivalence class are substitutable for each other, at least for some purposes. Specified by: `equals` in interface `Collection<K>` Specified by: `equals` in interface `Set<K>` Overrides: `equals` in class `Object` Parameters: `o` - the reference object with which to be compared for equality with this setcompare. Returns: `true` if the specifiedthis object is equal to this setthe same as the obj argument; `false` otherwise. See Also: `Object.equals(Object)` `Set.equals(Object)` `List.equals(Object)`hashCode() `HashMap`
### equals public boolean equals (Object o) Description copied from interface: `Set` Compares the specified object with this set for equality. Returns `true` if the specified object is also a set, the two sets have the same size, and every member of the specified set is contained in this set (or equivalently, every member of this set is contained in the specified set). This definition ensures that the equals method works properly across different implementations of the set interface. Specified by: `equals` in interface `Collection<K>` Specified by: `equals` in interface `Set<K>` Overrides: `equals` in class `Object` Parameters: `o` - object to be compared for equality with this set Returns: `true` if the specified object is equal to this set See Also: `Object.equals(Object)` `Set.equals(Object)` `List.equals(Object)` | ### equals public boolean equals (Object o) Description copied from class: `Object` Indicates whether some other object is "equal to" this one. The `equals` method implements an equivalence relation on non-null object references: It is reflexive: for any non-null reference value `x`, `x.equals(x)` should return `true`. It is symmetric: for any non-null reference values `x` and `y`, `x.equals(y)` should return `true` if and only if `y.equals(x)` returns `true`. It is transitive: for any non-null reference values `x`, `y`, and `z`, if `x.equals(y)` returns `true` and `y.equals(z)` returns `true`, then `x.equals(z)` should return `true`. It is consistent: for any non-null reference values `x` and `y`, multiple invocations of `x.equals(y)` consistently return `true` or consistently return `false`, provided no information used in `equals` comparisons on the objects is modified. For any non-null reference value `x`, `x.equals(null)` should return `false`. An equivalence relation partitions the elements it operates on into equivalence classes ; all the members of an equivalence class are equal to each other. Members of an equivalence class are substitutable for each other, at least for some purposes. Specified by: `equals` in interface `Collection<K>` Specified by: `equals` in interface `Set<K>` Overrides: `equals` in class `Object` Parameters: `o` - the reference object with which to compare. Returns: `true` if this object is the same as the obj argument; `false` otherwise. See Also: `Object.hashCode()` `HashMap`