MapConverter throws if extensions property is null

[PSanetra]

It seems like GraphQL.Client.Serializer.Newtonsoft.MapConverter expects properties of type Map to be never null. This is confusing as even the GraphQLResponse class declares the extensions property as Map?:

graphql-client/src/GraphQL.Primitives/GraphQLResponse.cs

Line 15 in d422bfd

public Map? Extensions { get; set; }

Related code:

graphql-client/src/GraphQL.Client.Serializer.Newtonsoft/MapConverter.cs

Line 20 in d422bfd

throw new ArgumentException("This converter can only parse when the root element is a JSON Object.");

There is also a related StackOverflow issue: https://stackoverflow.com/q/70884409/4019462