Ajust sys tests: don't passing explicit 'exists' to update.

firestore/tests/system.py

@@ -202,8 +202,7 @@ def test_document_integer_field(client, cleanup):
     document.create(data1)
 
     data2 = {'1a.ab': '4d', '6f.7g': '9h'}
-    option2 = client.write_option(exists=True)
-    document.update(data2, option=option2)
+    document.update(data2)
     snapshot = document.get()
     expected = {
         '1a': {
@@ -311,9 +310,8 @@ def test_update_document(client, cleanup):
     assert document_id in exc_info.value.message
 
     # 1. Try to update before the document exists (now with an option).
-    option1 = client.write_option(exists=True)
     with pytest.raises(NotFound) as exc_info:
-        document.update({'still': 'not-there'}, option=option1)
+        document.update({'still': 'not-there'})
     assert exc_info.value.message.startswith(MISSING_DOCUMENT)
     assert document_id in exc_info.value.message
 
@@ -327,8 +325,7 @@ def test_update_document(client, cleanup):
         },
         'other': True,
     }
-    option2 = client.write_option(exists=False)
-    write_result2 = document.update(data, option=option2)
+    write_result2 = document.create(data)
 
     # 3. Send an update without a field path (no option).
     field_updates3 = {'foo': {'quux': 800}}