SOURCE_FILE
  STRUCT
    VISIBILITY
      PUB_KW "pub"
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    STRUCT_KW "struct"
    WHITESPACE " "
    NAME
      IDENT "S"
    SEMICOLON ";"
  WHITESPACE "\n"
error 4: expected identifier, `self`, `super`, `crate`, or `Self`
