SOURCE_FILE
  COMMENT "// 2021"
  WHITESPACE "\n"
  ERROR
    PATH
      PATH_SEGMENT
        NAME_REF
          IDENT "gen"
  WHITESPACE " "
  FN
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "gen_fn"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        R_CURLY "}"
  WHITESPACE "\n"
  ERROR
    ASYNC_KW "async"
  WHITESPACE " "
  ERROR
    PATH
      PATH_SEGMENT
        NAME_REF
          IDENT "gen"
  WHITESPACE " "
  FN
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "async_gen_fn"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        R_CURLY "}"
  WHITESPACE "\n"
error 11: expected an item
error 32: expected fn, trait or impl
error 36: expected an item
