pythoningLearning
diff --git a/‎opc/package.py‎
Lines changed: 8 additions & 0 deletions b/‎opc/package.py‎
Lines changed: 8 additions & 0 deletions
diff --git a/‎tests/test_package.py‎
Lines changed: 13 additions & 0 deletions b/‎tests/test_package.py‎
Lines changed: 13 additions & 0 deletions
@@ -44,6 +44,14 @@ def rels(self):
         """
         return self._rels
 
+    def _add_relationship(self, reltype, target, rId, external=False):
+        """
+        Return newly added |_Relationship| instance of *reltype* between this
+        package and part *target* with key *rId*. Target mode is set to
+        ``RTM.EXTERNAL`` if *external* is |True|.
+        """
+        return self._rels.add_relationship(reltype, target, rId, external)
+
 
 class Part(object):
     """
 
@@ -59,6 +59,19 @@ def it_initializes_its_rels_collection_on_construction(
         RelationshipCollection_.assert_called_once_with(PACKAGE_URI.baseURI)
         assert pkg.rels == RelationshipCollection_.return_value
 
+    def it_can_add_a_relationship_to_a_part(self):
+        # mockery ----------------------
+        reltype, target, rId = (
+            Mock(name='reltype'), Mock(name='target'), Mock(name='rId')
+        )
+        pkg = OpcPackage()
+        pkg._rels = Mock(name='_rels')
+        # exercise ---------------------
+        pkg._add_relationship(reltype, target, rId)
+        # verify -----------------------
+        pkg._rels.add_relationship.assert_called_once_with(reltype, target,
+                                                           rId, False)
+
 
 class DescribePart(object):