A ConcurrentNavigableMap method tailMap() creates a view of the portion of this map whose keys are greater than or equal to fromKey. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. It returns a view of the portion of this map whose keys are greater than or equal to fromKey.

A ConcurrentNavigableMap method equals() compares the specified object with this map for equality. It returns boolean value true, if the given object is also a map and the two maps represent the same mappings, otherwise false.

A ConcurrentNavigableMap method size() determines number of entries present in this map. It returns the number of key-value mappings in this map.

A ConcurrentNavigableMap method putAll() copies all of the mappings from the specified map to this map. The effect of this call is equivalent to that of calling put(k, v) on this map once for each mapping from key k to value v in the specified map.

A ConcurrentNavigableMap method put() associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. It returns the previous value associated with key, or null if there was no mapping for key.

A ConcurrentNavigableMap method isEmpty() determines whether a map contains no key-value mappings. It returns boolean value true, if this map contains no key-value mappings, otherwise false.

A ConcurrentNavigableMap method hashCode() generates the hash code value for this map. The hash code of a map is defined to be the sum of the hash codes of each entry in the map's entrySet() view. It returns the hash code value for this map.

A ConcurrentNavigableMap method get() retrieves the value to which the specified key is mapped. It returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.

A ConcurrentNavigableMap method containsValue() determines whether a specified value present in this map. It returns boolean value true, if specified value in this map, otherwise false.

A ConcurrentNavigableMap method containsKey() determines whether a specified key present in this map. It returns boolean value true, if specified key in this map, otherwise false.