interface Pet {
  name: String!
}

enum DogCommand {
  SIT
  HEEL
}

enum CatCommand {
  JUMP
}

type Query {
  pet: Pet
}

type Dog implements Pet {
  name: String!
  nickname: String!
  barkVolume: Int!
  doesKnowCommand(dogCommand: DogCommand!): Boolean!
  isAtLocation(x: Int, y: Int): Boolean!
}

type Cat implements Pet {
  name: String!
  meowVolume: Int!
  doesKnowCommand(catCommand: CatCommand!): Boolean!
}

query barkVolume {
  pet {
    ...safeDifferingFields
  }
}

query doesKnowCommand {
  pet {
    ...safeDifferingArgs
  }
}

query isAtLocation {
  pet {
    ...safeDifferingArgOrder
  }
}

fragment safeDifferingFields on Pet {
  ... on Dog {
    volume: barkVolume
  }
  ... on Cat {
    volume: meowVolume
  }
}

fragment safeDifferingArgs on Pet {
  ... on Dog {
    doesKnowCommand(dogCommand: SIT)
  }
  ... on Cat {
    doesKnowCommand(catCommand: JUMP)
  }
}

fragment safeDifferingArgOrder on Dog {
  isAtLocation(x: 0, y: 0)
  isAtLocation(y: 0, x: 0)
}