Create batch class (#1183)

* Create batch class

* add simple reno and test

qiskit_ibm_runtime/__init__.py

@@ -181,6 +181,7 @@ def result_callback(job_id, result):
 from .runtime_options import RuntimeOptions
 from .utils.json import RuntimeEncoder, RuntimeDecoder
 from .session import Session  # pylint: disable=cyclic-import
+from .batch import Batch  # pylint: disable=cyclic-import
 
 from .exceptions import *
 from .utils.utils import setup_logger

qiskit_ibm_runtime/batch.py

@@ -0,0 +1,21 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2023.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""Qiskit Runtime batch mode."""
+
+from .session import Session
+
+
+class Batch(Session):
+    """Class for creating a batch mode in Qiskit Runtime."""
+
+    pass

releasenotes/notes/batch-class-b7a3befcfce8860e.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    There is a new class, :class:`qiskit_ibm_runtime.Batch` that currently works
+    the same way as :class:`qiskit_ibm_runtime.Session` but will later be updated 
+    to better support submitting multiple jobs at once.

test/unit/test_batch.py

@@ -0,0 +1,35 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2022.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""Tests for Batch class."""
+
+from unittest.mock import patch
+
+from qiskit_ibm_runtime import Batch
+import qiskit_ibm_runtime.session as session_pkg
+from ..ibm_test_case import IBMTestCase
+
+
+class TestBatch(IBMTestCase):
+    """Class for testing the Session class."""
+
+    def tearDown(self) -> None:
+        super().tearDown()
+        session_pkg._DEFAULT_SESSION.set(None)
+
+    @patch("qiskit_ibm_runtime.session.QiskitRuntimeService", autospec=True)
+    def test_default_batch(self, mock_service):
+        """Test using default batch mode."""
+        mock_service.global_service = None
+        batch = Batch(backend="ibm_gotham")
+        self.assertIsNotNone(batch.service)
+        mock_service.assert_called_once()