private void createFunctionDefinition(String functionName, String... paramNames) {
		ProgramDataTypeManager dataTypeManager = program.getDataTypeManager();
		int id = dataTypeManager.startTransaction("test");
		FunctionDefinitionDataType dt = new FunctionDefinitionDataType(functionName);
		ParameterDefinition[] args = new ParameterDefinition[paramNames.length];
		for (int i = 0; i < paramNames.length; i++) {
			args[i] = new ParameterDefinitionImpl(paramNames[i], new ByteDataType(), null);
		}
		dt.setArguments(args);
		dataTypeManager.addDataType(dt, null);
		dataTypeManager.endTransaction(id, true);
	}
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