Rewrite TimeDelta serialization test
Rewrite TimeDelta serialization test
bartaelterman/marshmallow,dwieeb/marshmallow,quxiaolong1504/marshmallow,marshmallow-code/marshmallow,daniloakamine/marshmallow,xLegoz/marshmallow,maximkulkin/marshmallow,Bachmann1234/marshmallow,VladimirPal/marshmallow,etataurov/marshmallow,Tim-Erwin/marshmallow,mwstobo/marshmallow