function createUnboundRelationshipTransformer (config) {
  const unboundRelationshipTransformer = v4x4.createUnboundRelationshipTransformer(config)
  return unboundRelationshipTransformer.extendsWith({
    fromStructure: struct => {
      structure.verifyStructSize(
        'UnboundRelationship',
        UNBOUND_RELATIONSHIP_STRUCT_SIZE,
        struct.size
      )

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

      return new UnboundRelationship(
        identity,
        type,
        properties,
        elementId
      )
    }
  })
}
Create an extend Unbound Relationship transformer with support to elementId
@param {any} config
@returns {TypeTransformer}