Remove get_transaction_class method

gramps/gen/db/generic.py

@@ -1590,12 +1590,6 @@ class DbGeneric(DbWriteBase, DbReadBase, UpdateCallback, Callback):
                     handle = str(handle, "utf-8")
                 map[handle] = class_.create(data)
 
-    def get_transaction_class(self):
-        """
-        Get the transaction class associated with this database backend.
-        """
-        return DbGenericTxn
-
     def get_from_name_and_handle(self, table_name, handle):
         """
         Returns a gen.lib object (or None) given table_name and

gramps/gen/lib/test/field_test.py

@@ -22,7 +22,7 @@
 
 import unittest
 
-from gramps.gen.db import make_database
+from gramps.gen.db import make_database, DbTxn
 
 from  ..import (Person, Surname, Name, NameType, Family, FamilyRelType,
                 Event, EventType, Source, Place, PlaceName, Citation, Date,
@@ -38,7 +38,7 @@ class FieldBaseTest(unittest.TestCase):
     def setUp(self):
         db = make_database("inmemorydb")
         db.load(None)
-        with db.get_transaction_class()("Test", db) as trans:
+        with DbTxn("Test", db) as trans:
             # Add some people:
             person1 = Person()
             person1.primary_name = Name()

gramps/plugins/db/bsddb/write.py

@@ -2463,12 +2463,6 @@ class DbBsddb(DbBsddbRead, DbWriteBase, UpdateCallback):
         """
         return self.brief_name
 
-    def get_transaction_class(self):
-        """
-        Get the transaction class associated with this database backend.
-        """
-        return DbTxn
-
     def backup(self, user=None):
         """
         Exports the database to a set of backup files. These files consist