Convert backward compatibility to real test.

slapos/libnetworkcachetests.py

@@ -98,10 +98,16 @@ class TestNetworkcacheClient(LibNetworkCacheMixin):
     url = 'http://%s:%s' % (self.host, self.port)
     self.shacache_url = url + self.shacache_path
     self.shadir_url = url + self.shadir_path
-    # checking the backwards compatibilty
     self.nc = NetworkcacheClient(shacache=self.shacache_url,
                                  shadir=self.shadir_url)
 
+  def test_init_backward_compatible(self):
+    """Checks that invocation with minimal parameter works fine"""
+    nc = NetworkcacheClient(shacache=self.shacache_url,
+                                 shadir=self.shadir_url)
+    self.assertEqual(nc.shacache_url, self.shacache_url)
+    self.assertTrue(nc.shadir_host in self.shadir_url)
+
   def test_init_method_normal_http_url(self):
     """
       Check if the init method is setting the attributes correctly.