Is possible to typing typeConfig of graphql.Object after Object done.

In fact , I am trying to write a schema parser to load definition from schema. https://github.com/tawalisa/GraphQL-Go-schema-parser
But I found the typeConfig is private once the Object is initial. In graphql-java, we still change resolver when schema initial done. But in graphql-go, we can not access typeConfig. Just is there any way to change resolver when schema initial done?

https://github.com/graphql-go/graphql/blob/master/definition.go#L342