suggested supplement to docs on polymorphism

Documentation at https://swagger.io/docs/specification/v3_0/data-models/inheritance-and-polymorphism/ includes this text:

Mapping Type Names

It is implied, that the property to which discriminator refers, contains the name of the target schema. In the example above, the objectType property should contain either simpleObject, or complexObject string. If the property values do not match the schema names, you can map the values to the names. To do this, use the discriminator/mapping keyword:

It seems to me that the docs should point out that this can and should be enforced using enum: like this:

            simpleObject:
              type: object       
              required:
                - objectType       
              properties:
                objectType:
                  type: string
                  enum: [simpleObject]
            complexObject:
              type: object       
              required:
                - objectType       
              properties:
                objectType:
                  type: string
                  enum: [complexObject]

Start with the “Mapping Type Names” section at the Swagger documentation URL in the issue and review how the discriminator examples describe matching property values. Add guidance that matching can be enforced with an enum and include the supplied schema example. The documentation is done when the recommendation and example are clear and consistent with the surrounding polymorphism guidance.