protected Collection<DR> getDataChildrenOf(NR parent) {
		return cachedDataChildren.computeIfAbsent(parent.getKey(),
			k -> new ArrayList<>(getDataChildrenOf(k)));
	}
For leaf nodes, get the children.

For non-leaf nodes, the behavior is undefined. Note that the query should not filter the
children, only order them, or else the collection will return an incorrect
{@link Collection#size()}. Filtering is performed by {@link TreeRecordVisitor}.

@param parent the parent node
@param query a query to control the ordering of the children
@return a collection of the children
Ghidra/Debug/ProposedUtils/src/main/java/ghidra/util/database/spatial/AbstractConstraintsTree.java