private Archive getSingleDTArchive(List<GTreeNode> nodes) {

		Archive dtArchive = null;
		for (GTreeNode node : nodes) {
			Archive archive = findArchive(node);
			if (dtArchive == null) {
				dtArchive = archive;
				continue;
			}

			if (dtArchive != archive) {
				return null;
			}
		}
		return dtArchive;
	}
Allows the user to associate the selected action with a source archive.  An associate data type
allows users to push changes to the source archive and to pull updates from the source archive.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/actions/associate/AssociateDataTypeAction.java