private Map<String, Structure> getStructures(DataTypesProvider resultsProvider) {

		Map<String, Structure> map = new HashMap<>();
		DataTypeArchiveGTree gTree = resultsProvider.getGTree();
		GTreeNode rootNode = gTree.getViewRoot();
		Iterator<GTreeNode> it = rootNode.iterator(true);
		for (GTreeNode node : CollectionUtils.asIterable(it)) {
			if (!(node instanceof DataTypeNode)) {
				continue;
			}
			DataTypeNode dtNode = (DataTypeNode) node;
			DataType dt = dtNode.getDataType();
			if (dt instanceof Structure) {
				map.put(dt.getName(), (Structure) dt);
			}
		}

		return map;
	}
Tests for managing categories through the data manager plugin and tests for
actions being enabled when a node is selected.
Ghidra/Features/Base/src/test.slow/java/ghidra/app/plugin/core/datamgr/DataTypeManagerPluginTest.java