upload config

venv/lib/python3.9/site-packages/pip/_internal/resolution/base.py

@@ -0,0 +1,21 @@
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Callable, List
+
+    from pip._internal.req.req_install import InstallRequirement
+    from pip._internal.req.req_set import RequirementSet
+
+    InstallRequirementProvider = Callable[
+        [str, InstallRequirement], InstallRequirement
+    ]
+
+
+class BaseResolver(object):
+    def resolve(self, root_reqs, check_supported_wheels):
+        # type: (List[InstallRequirement], bool) -> RequirementSet
+        raise NotImplementedError()
+
+    def get_installation_order(self, req_set):
+        # type: (RequirementSet) -> List[InstallRequirement]
+        raise NotImplementedError()