Person:
  firstName: String!
  lastName: String!

Topic:
  name: String!

SkillLevel:
  name: String!
  weight: Float!

Skill:
  person: Person!
  topic: Topic!
  level: SkillLevel!

TopicRelationType:
  name: String!

TopicRelation:
  summary: String!
  from: Topic!
  to: Topic!
  type: TopicRelationType!