SOURCE_FILE
  EXTERN_BLOCK
    UNSAFE_KW "unsafe"
    WHITESPACE " "
    ABI
      EXTERN_KW "extern"
      WHITESPACE " "
      STRING "\"C\""
    WHITESPACE " "
    EXTERN_ITEM_LIST
      L_CURLY "{"
      R_CURLY "}"
  WHITESPACE "\n"
  EXTERN_BLOCK
    ABI
      EXTERN_KW "extern"
    WHITESPACE " "
    EXTERN_ITEM_LIST
      L_CURLY "{"
      R_CURLY "}"
  WHITESPACE "\n"
