type: map
required: yes
mapping:
 "teams":
    type: seq
    required: yes
    sequence:
      - &team
        type:  map
        required: yes
        class:  Team
        mapping:
         "name":  {type: str, required: yes, unique: yes}
         "desc":  {type: str}
         "chief":  *member       # preceding alias
         "members":
            type: seq
            sequence: [*member]  # preceding alias
 "members":
    type: seq
    required: yes
    sequence:
      - &member
        type:  map
        required: yes
        class:  Member
        mapping:
         "name":  {type: str, required: yes, unique: yes}
         "desc":  {type: str}
         "team":  *team