in src/main/java/org/apache/sling/jcr/base/internal/mount/ProxySession.java [573:581]
public void move(String srcAbsPath, String destAbsPath) throws ItemExistsException, PathNotFoundException, VersionException, ConstraintViolationException, LockException, RepositoryException {
if (isMount(srcAbsPath) && isMount(destAbsPath)) {
this.mount.move(srcAbsPath, destAbsPath);
} else if (!isMount(srcAbsPath) && !isMount(destAbsPath)) {
this.jcr.move(srcAbsPath, destAbsPath);
} else {
throw new IllegalStateException("Move between jcr and mount not supported");
}
}