Fix bug with retrieving fake backends (#1402)

* bug fix w retrieving fake backend

* Move test

qiskit_ibm_runtime/fake_provider/fake_provider.py

@@ -75,7 +75,7 @@ def backend(self, name=None, **kwargs):  # type: ignore
         """
         backend = self._backends[0]
         if name:
-            filtered_backends = [backend for backend in self._backends if backend.name() == name]
+            filtered_backends = [backend for backend in self._backends if backend.name == name]
             if not filtered_backends:
                 raise QiskitBackendNotFoundError()
 

releasenotes/notes/retrieve-fake-backend-13fd3088aaac69e5.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fixed a bug where retrieving a fake backend through ``FakeProviderForBackendV2.backend()``
+    would result in a type error. 

test/unit/fake_provider/test_fake_backends.py

@@ -17,7 +17,7 @@
 from qiskit import QuantumRegister, ClassicalRegister, QuantumCircuit, transpile
 from qiskit.utils import optionals
 
-from qiskit_ibm_runtime.fake_provider import FakeAthens, FakePerth
+from qiskit_ibm_runtime.fake_provider import FakeAthens, FakePerth, FakeProviderForBackendV2
 from ...ibm_test_case import IBMTestCase
 
 
@@ -60,3 +60,10 @@ def test_fake_backend_v2_noise_model_always_present(self):
         res = backend.run(qc, shots=1000).result().get_counts()
         # Assert noise was present and result wasn't ideal
         self.assertNotEqual(res, {"1": 1000})
+
+    def test_retrieving_single_backend(self):
+        """Test retrieving a single backend."""
+        provider = FakeProviderForBackendV2()
+        backend_name = "fake_jakarta"
+        backend = provider.backend(backend_name)
+        self.assertEqual(backend.name, backend_name)