gistfile1.txt

On schoolTeacher resource:
{
  _items: [
    {
      _id: 1234
      ...
      _links: {
        befriend/poolWith/etc: {
          href: "/api/teacher/1234/friends",
          method: "POST",
          schema: {
            properties: {
              code: {
               type: "string"
               required: true
              }
            }
          }
        }
      }
    },
    {
      _id: 5678
      ...
        _links: {
        befriend/poolWith/etc: {
          href: "/api/teacher/5678/friends",
          method: "POST",
          schema: {
            properties: {
              code: {
               type: "string"
               required: true
              }
            }
          }
        }
      }
    }
  ]
}