Return an empty list in KojiResolver.get_compatible_base_module_modulemds.

For KojiResolver, this method returns always an empty list. The compatible modules are
defined by the Koji tag inheritance, so there is no need to find out the compatible
base modules on MBS side.

This makes `mse.get_base_module_mmds` to ignore virtual streams and just use
the input base module as the only module without finding the compatible
base modules.

module_build_service/resolver/KojiResolver.py

@@ -160,3 +160,11 @@ class KojiResolver(DBResolver):
             mmds.append(module.mmd())
 
         return mmds
+
+    def get_compatible_base_module_modulemds(self, *args, **kwargs):
+        """
+        For KojiResolver, this method returns always an empty list. The compatible modules are
+        defined by the Koji tag inheritance, so there is no need to find out the compatible
+        base modules on MBS side.
+        """
+        return []

tests/test_resolver/test_koji.py

@@ -26,7 +26,7 @@ from datetime import datetime
 
 import module_build_service.resolver as mbs_resolver
 from module_build_service.utils.general import import_mmd, mmd_to_str, load_mmd
-from module_build_service.models import ModuleBuild
+from module_build_service.models import ModuleBuild, BUILD_STATES
 import tests
 
 
@@ -212,3 +212,12 @@ class TestLocalResolverModule:
         assert nvrs == {
             "testmodule-master-20170110091357.7c29193d",
             "testmodule-2-20180109091357.7c29193d"}
+
+    def test_get_compatible_base_module_modulemds(self, db_session):
+        tests.init_data(1, multiple_stream_versions=True)
+        resolver = mbs_resolver.GenericResolver.create(db_session, tests.conf, backend="koji")
+        result = resolver.get_compatible_base_module_modulemds(
+            "platform", "f29.1.0", stream_version_lte=True, virtual_streams=["f29"],
+            states=[BUILD_STATES["ready"]])
+
+        assert len(result) == 0