@Override
		public NavigableSet<S> spans() {
			// Make this a view?
			return spanTree.values()
					.stream()
					.map(e -> e.getKey())
					.collect(Collectors.toCollection(TreeSet::new));
		}
Create a span map on the given domain

<p>
Extensions should invoke this as a super constructor with a fixed domain. See
{@link DefaultULongSpanMap} for an example.

@param domain the domain
Ghidra/Framework/Emulation/src/main/java/generic/Span.java