move skip_if_empty to separate function for test coverage
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 6c8d088..8bb8422 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -32,7 +32,7 @@
     load_fips_ecdsa_key_pair_vectors, load_fips_ecdsa_signing_vectors,
     load_hash_vectors, load_kasvs_dh_vectors, load_nist_vectors,
     load_pkcs1_vectors, load_rsa_nist_vectors, load_vectors_from_file,
-    raises_unsupported_algorithm, select_backends
+    raises_unsupported_algorithm, select_backends, skip_if_empty
 )
 
 
@@ -82,6 +82,13 @@
     assert selected_backends == [b1, b2]
 
 
+def test_skip_if_empty():
+    with pytest.raises(pytest.skip.Exception):
+        skip_if_empty([], [FakeInterface])
+
+    skip_if_empty(["notempty"], [FakeInterface])
+
+
 def test_check_backend_support_skip():
     supported = pretend.stub(
         kwargs={"only_if": lambda backend: False, "skip_message": "Nope"}