add class variable to reduce const_get calls
add class variable to reduce const_get calls

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