feat: add basic batch feature, data model and partial handler

hopefully data model is complete enough for now, but handler does not
yet have all methods, e.g. execute()

tests/db/model/test_batch.py

@@ -0,0 +1,52 @@
+# -*- coding: utf-8; -*-
+
+import uuid as _uuid
+
+from wuttjamaican.testing import DataTestCase
+
+try:
+    import sqlalchemy as sa
+    from wuttjamaican.db import model
+    from wuttjamaican.db.model import batch as mod
+except ImportError:
+    pass
+else:
+
+    class TestBatchMixin(DataTestCase):
+
+        def test_basic(self):
+
+            class MyBatch(mod.BatchMixin, model.Base):
+                __tablename__ = 'testing_mybatch'
+
+            model.Base.metadata.create_all(bind=self.session.bind)
+            metadata = sa.MetaData()
+            metadata.reflect(self.session.bind)
+            self.assertIn('testing_mybatch', metadata.tables)
+
+            batch = MyBatch(id=42, uuid=_uuid.UUID('0675cdac-ffc9-7690-8000-6023de1c8cfd'))
+            self.assertEqual(repr(batch), "MyBatch(uuid=UUID('0675cdac-ffc9-7690-8000-6023de1c8cfd'))")
+            self.assertEqual(str(batch), "00000042")
+
+
+    class TestBatchRowMixin(DataTestCase):
+
+        def test_basic(self):
+
+            class MyBatch2(mod.BatchMixin, model.Base):
+                __tablename__ = 'testing_mybatch2'
+
+            class MyBatchRow2(mod.BatchRowMixin, model.Base):
+                __tablename__ = 'testing_mybatch_row2'
+                __batch_class__ = MyBatch2
+
+            model.Base.metadata.create_all(bind=self.session.bind)
+            metadata = sa.MetaData()
+            metadata.reflect(self.session.bind)
+            self.assertIn('testing_mybatch2', metadata.tables)
+            self.assertIn('testing_mybatch_row2', metadata.tables)
+
+            # nb. this gives coverage but doesn't really test much
+            batch = MyBatch2(id=42, uuid=_uuid.UUID('0675cdac-ffc9-7690-8000-6023de1c8cfd'))
+            row = MyBatchRow2()
+            batch.rows.append(row)