UnionWIth multuple documents

In my Java code, I have a bunch of bson.Document instances that each represent a working MongoDB query.

I want to group them into a single document that can execute all of the queries at once as a union.

Easier to explain in code. Can you implement the following method:
Can you implement this method in Java …

public void runAllAsUnion(Document documents...){
// Where documents... is an arbitrary length array 
// Use a unionWith or any other operation that will combine the results