Is there an AddRange equivalent for a HashSet in C#

With a list you can do:

list.AddRange(otherCollection);

There is no add range method in a HashSet.
What is the best way to add another ICollection to a HashSet?

For HashSet, the name is UnionWith.

This is to indicate the distinct way the HashSet works. You cannot safely Add a set of random elements to it like in Collections, some elements may naturally evaporate.

I think that UnionWith takes its name after "merging with another HashSet", however, there's an overload for IEnumerable too.

Stack Overflow Q#15267034, score: 882