refactor(Serialize) make some methods private
refactor(Serialize) make some methods private

rmosolgo/graphql-ruby,xuorig/graphql-ruby,xuorig/graphql-ruby,nevesenin/graphql-ruby,nevesenin/graphql-ruby,xuorig/graphql-ruby,nevesenin/graphql-ruby,nevesenin/graphql-ruby,rmosolgo/graphql-ruby,rmosolgo/graphql-ruby,rmosolgo/graphql-ruby