While parsing yaml it generates invalid tag for mapping

Content of data.yaml file

name: !!set
  ? Mike
  ? Tyson
  ? Broke Lesner

data.yaml file storing set data and its valid I have tested it on https://www.yamllint.com/ but it generates error during parsing

File("data.yaml")
      .readAsString()
      .then(loadYamlDocuments)
      .then(print);

Error that's generated:

Unhandled exception:

Error : Invalid tag for mapping.
   ╷
26 │   name: !!set
   │ ┌───────^
27 │ │   ? Mike
   │ └──^