[
  {"type":"Name","value":"extra"},
  {"type":"Text","value":" "},
  {"type":"Operator","value":"="},
  {"type":"Text","value":" "},
  {"type":"LiteralStringAffix","value":"f"},
  {"type":"LiteralStringSingle","value":"'"},
  {"type":"LiteralStringInterpol","value":"{"},
  {"type":"Name","value":"extra"},
  {"type":"LiteralStringInterpol","value":"}"},
  {"type":"LiteralStringSingle","value":",waiters:"},
  {"type":"LiteralStringInterpol","value":"{"},
  {"type":"NameBuiltin","value":"len"},
  {"type":"Punctuation","value":"("},
  {"type":"NameBuiltinPseudo","value":"self"},
  {"type":"Operator","value":"."},
  {"type":"Name","value":"_waiters"},
  {"type":"Punctuation","value":")"},
  {"type":"LiteralStringInterpol","value":"}"},
  {"type":"LiteralStringSingle","value":"'"},
  {"type":"Text","value":"\n"}
]