* Get the namespace declared at the package level, and ensure the the
* given namespace is not redundant with that package-level namespace.
*/
final XmlSchema schema = impl.getPackage().getAnnotation(XmlSchema.class);
assertNotNull("Missing @XmlSchema package annotation.", schema);
final String schemaNamespace = schema.namespace();
assertFalse("Missing namespace in @XmlSchema package annotation.", schemaNamespace.trim().isEmpty());
assertFalse("Namespace declaration is redundant with @XmlSchema.", namespace.equals(schemaNamespace));
/*
* Check that the namespace is declared in the package-level @XmlNs annotation.
* We do not verify the validity of those @XmlNs annotations, since this is the