Added close_session

qiskit_ibm_provider/ibm_backend.py

@@ -883,6 +883,16 @@ def session(self) -> Session:
 
     def cancel_session(self) -> None:
         """Cancel session. All pending jobs will be cancelled."""
+        if self._session:
+            self._session.cancel()
+            if self._session.session_id:
+                self.provider._runtime_client.cancel_session(self._session.session_id)
+        self._session = None
+
+    def close_session(self) -> None:
+        """Close the session so new jobs will no longer be accepted, but existing
+        queued or running jobs will run to completion. The session will be terminated once there
+        are no more pending jobs."""
         if self._session:
             self._session.cancel()
             if self._session.session_id: