GraphQL - how to write custom resolver interface field

I am writing a custom resolver for interface field but it's never been called.

interface Entity {
  resolverPoint(args: EntityType): String
}

This is Resolver

const resolvers = {
    Entity: {
       resolverPoint: (obj){
         return ''
       }
    }
}

Interface fields cannot have implementations (pretty much like in many programming languages). Each of the types that implement the model must define their own resolver for this field.

interface Entity {
  resolverPoint(args: EntityType): String
}

type ImplementingType implements Entity {
  resolverPoint(args: EntityType): String
}

This will be called now:

const resolvers = {
    ImplementingType: {
       resolverPoint: (obj){
         return ''
       }
    }
}

At least this is how the packages graphql-tools and graphql work. There are maybe other implementations that allow implementing types to inherit resolvers.