*/
private Namespace computeNamespace(ImportDirective importDirective) {
Namespace namespace = namespaceMap.get(importDirective);
if (namespace == null) {
// If the namespace isn't in the namespaceMap, then compute and put it in the map
ImportElement importElement = importDirective.getElement();
if (importElement != null) {
NamespaceBuilder builder = new NamespaceBuilder();
namespace = builder.createImportNamespaceForDirective(importElement);
namespaceMap.put(importDirective, namespace);
}