Merge fork changes.

stix2/sources/__init__.py

@@ -412,9 +412,7 @@ class DataSource(object):
             stix_obj (dictionary): the STIX object to be returned
 
         """
-        stix_obj = None
-
-        return stix_obj
+        raise NotImplementedError()
 
     @abc.abstractmethod
     def all_versions(self, id_, _composite_filters=None):

stix2/test/test_data_sources.py

@@ -0,0 +1,22 @@
+import pytest
+
+import stix2.sources
+
+
+def test_data_source():
+    ds = stix2.sources.DataSource()
+
+    assert ds.name == "DataSource"
+
+
+def test_set_data_source_name():
+    ds = stix2.sources.DataSource(name="My Data Source")
+
+    assert ds.name == "My Data Source"
+
+
+def test_data_source_get():
+    ds = stix2.sources.DataSource(name="My Data Source")
+
+    with pytest.raises(NotImplementedError):
+        ds.get("foo")