Adds all of the elements in the specified Collection to this set.
Adds all of the elements in the specified Collection to this set. NULL elements added are silently ignored.For hash sets this method has a time complexity of O(M), with M being the size of the collection whose elements are added.
For tree sets this method has a time complexity of O(M * Log N), with M being the size of the collection whose elements are added, and N being the number of elements in the set.