Project project = CreateTestProjectWithCustomField();

// Set formula for extended attribute
project.getExtendedAttributes().get(0).setFormula("\"Total tasks: \" & [Task Count] & \" Total resources: \" & [Resource Count]");
        
// Print value of extened attribute
Task task = project.getRootTask().getChildren().getById(1);
System.out.println("Formula with boolean values" + task.getExtendedAttributes().get(0).getTextValue());