function createUnboundRelationshipTransformer () {
  return new TypeTransformer({
    signature: UNBOUND_RELATIONSHIP,
    isTypeInstance: object => object instanceof UnboundRelationship,
    toStructure: object => {
      throw newError(
        `It is not allowed to pass unbound relationships in query parameters, given: ${object}`,
        PROTOCOL_ERROR
      )
    },
    fromStructure: struct => {
      structure.verifyStructSize(
        'UnboundRelationship',
        UNBOUND_RELATIONSHIP_STRUCT_SIZE,
        struct.size
      )

      const [identity, type, properties] = struct.fields

      return new UnboundRelationship(identity, type, properties)
    }
  })
}
Creates the Unbound Relationship Transformer
@returns {TypeTransformer}