@Override
	public boolean hasNext() {
		return !queue.isEmpty();
	}
Construct a merge-sorting iterator which generates labeled values

<p>
The map of iterators is a map of entries, each giving a label and an iterator to be merged.
Each iterator must return values as sorted by the given comparator. The entries returned by
the combined iterator give the values in sorted order, but each has a the key indicating
which given iterator returned that value. Note that the returned entry may be re-used by the
underlying implementation, so users needing to keep the entry should create a copy.

@param iterMap a map of labeled iterators
@param comparator the comparator of values
@return an iterator which returns labeled values in sorted order
Ghidra/Debug/ProposedUtils/src/main/java/ghidra/util/MergeSortingIterator.java