// Copied from org.eclipse.ocl.examples.test.xtext.PivotDocumentationExamples.java

		Library library = getLibrary(resourceSet);  // get library from a hypothetical source

		// use the constraints defined in the OCL document

		// use getBooks() from the document in another query to find a book
		ExpressionInOCL expression = ocl.createQuery(EXTLibraryPackage.Literals.LIBRARY,
		    "getBooks('Bleak House')->asSequence()->first()");

		Book book = (Book) ocl.evaluate(library, expression);
		debugPrintf("Got book: %s%n\n", book);

		// use the unique_title constraint to validate the book
		boolean isValid = ocl.check(book, constraintMap.get("unique_title"));
		debugPrintf("Validate book: %b%n\n", isValid);	
