public TaintSet union(TaintSet that) {
		Set<TaintMark> marks = new HashSet<>();
		// TODO: What's the most efficient data structure here?
		marks.addAll(this.marks);
		marks.addAll(that.marks);
		return of(marks);
	}
Construct the taint set from the union of marks of this and the given taint set

@param that another taint set
@return the union
Ghidra/Debug/TaintAnalysis/src/main/java/ghidra/taint/model/TaintSet.java