From e8d6ba9f5d1bc5676ccf5864821c1959671b9698 Mon Sep 17 00:00:00 2001
From: Luciano Bello <bel@zurich.ibm.com>
Date: Wed, 13 Nov 2024 18:52:43 +0100
Subject: [PATCH] remove deprecated Provider ABC
 https://github.com/Qiskit/qiskit/pull/12145

---
 qiskit/providers/backend.py                   | 25 +++++++++++++++++--
 .../basic_provider/basic_simulator.py         |  4 +++
 test/utils/base.py                            |  3 +--
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/qiskit/providers/backend.py b/qiskit/providers/backend.py
index 93b31308e21..327704fc1f0 100644
--- a/qiskit/providers/backend.py
+++ b/qiskit/providers/backend.py
@@ -86,7 +86,7 @@ def __init__(self, configuration, provider=None, **fields):
         Args:
             configuration (BackendConfiguration): A backend configuration
                 object for the backend object.
-            provider (qiskit.providers.Provider): Optionally, the provider
+            provider: Optionally, the provider
                 object that this Backend comes from.
             fields: kwargs for the values to use to override the default
                 options.
@@ -158,6 +158,14 @@ def properties(self):
         """
         return None
 
+    def provider(self):
+        """Return the backend provider.
+
+        Returns:
+            provider: the provider responsible for the backend.
+        """
+        return self._provider
+
     def status(self):
         """Return the backend status.
 
@@ -242,7 +250,7 @@ class QubitProperties:
 
     This class provides the optional properties that a backend can provide for
     a qubit. These represent the set of qubit properties that Qiskit can
-    currently work with if present. However, if your backend provides additional
+    currently work with if present. However if your backend provides additional
     properties of qubits you should subclass this to add additional custom
     attributes for those custom/additional properties provided by the backend.
     """
@@ -318,6 +326,7 @@ class BackendV2(Backend, ABC):
 
     def __init__(
         self,
+        provider=None,
         name: str = None,
         description: str = None,
         online_date: datetime.datetime = None,
@@ -327,6 +336,8 @@ def __init__(
         """Initialize a BackendV2 based backend
 
         Args:
+            provider: An optional backwards reference to the provider
+                object that the backend is from
             name: An optional name for the backend
             description: An optional description of the backend
             online_date: An optional datetime the backend was brought online
@@ -345,6 +356,7 @@ def __init__(
         """
 
         self._options = self._default_options()
+        self._provider = provider
         if fields:
             for field in fields:
                 if field not in self._options.data:
@@ -617,6 +629,15 @@ def options(self):
         """
         return self._options
 
+    @property
+    def provider(self):
+        """Return the backend provider.
+
+        Returns:
+            provider: the provider responsible for the backend.
+        """
+        return self._provider
+
     @abstractmethod
     def run(self, run_input, **options):
         """Run on the backend.
diff --git a/qiskit/providers/basic_provider/basic_simulator.py b/qiskit/providers/basic_provider/basic_simulator.py
index 71d0459c054..2101f921c84 100644
--- a/qiskit/providers/basic_provider/basic_simulator.py
+++ b/qiskit/providers/basic_provider/basic_simulator.py
@@ -73,11 +73,14 @@ class BasicSimulator(BackendV2):
 
     def __init__(
         self,
+        provider=None,
         target: Target | None = None,
         **fields,
     ) -> None:
         """
         Args:
+            provider: An optional backwards reference to the provider object that the backend
+                is from.
             target: An optional target to configure the simulator.
             fields: kwargs for the values to use to override the default
                 options.
@@ -88,6 +91,7 @@ def __init__(
         """
 
         super().__init__(
+            provider=provider,
             name="basic_simulator",
             description="A python simulator for quantum experiments",
             backend_version="0.1",
diff --git a/test/utils/base.py b/test/utils/base.py
index 133666cfc7a..5872b896293 100644
--- a/test/utils/base.py
+++ b/test/utils/base.py
@@ -235,8 +235,7 @@ def tearDown(self):
         # due to importing the instances from the top-level qiskit namespace.
         from qiskit.providers.basic_provider import BasicProvider
 
-        with self.assertWarns(DeprecationWarning):
-            BasicProvider()._backends = BasicProvider()._verify_backends()
+        BasicProvider()._backends = BasicProvider()._verify_backends()
 
     def assertQuantumCircuitEqual(self, qc1, qc2, msg=None):
         """Extra assertion method to give a better error message when two circuits are unequal."""