The FXMLLoader.load() documentation states:

> When the "template" flag is set to false (the default), this method will clear the imports before loading the document's content. When "template" is true, the imports will not be cleared, and the root value will be set to null before the content is loaded. This helps improve performance on subsequent loads by eliminating the overhead of loading the classes referred to by the document.

However, there is no API to set a "template" flag.

http://docs.oracle.com/javase/8/javafx/api/javafx/fxml/FXMLLoader.html#load--