Expand coverage for _body_bytes methods

Author: adamtheturtle

tests/mock_vws/fixtures/prepared_requests.py

@@ -113,7 +113,9 @@ def delete_target(
     date = rfc_1123_date()
     request_path = f"/targets/{target_id}"
     method = HTTPMethod.DELETE
-    content = b""
+    # This could be b"" or None, but we want to exercise handling
+    # all three of those types.
+    content = ""
 
     access_key = vuforia_database.server_access_key
     secret_key = vuforia_database.server_secret_key
@@ -158,7 +160,9 @@ def database_summary(vuforia_database: VuforiaDatabase) -> Endpoint:
     request_path = "/summary"
     method = HTTPMethod.GET
 
-    content = b""
+    # This could be b"" or "", but we want to exercise handling
+    # all three of those types.
+    content = None
 
     access_key = vuforia_database.server_access_key
     secret_key = vuforia_database.server_secret_key