SOURCE_FILE
  ATTR
    POUND "#"
    BANG "!"
    L_BRACK "["
    CFG_ATTR_META
      CFG_ATTR_KW "cfg_attr"
      L_PAREN "("
      CFG_COMPOSITE
        IDENT "not"
        L_PAREN "("
        CFG_ATOM
          IDENT "foo"
        R_PAREN ")"
      COMMA ","
      WHITESPACE " "
      UNSAFE_META
        UNSAFE_KW "unsafe"
        L_PAREN "("
        TOKEN_TREE_META
          PATH
            PATH_SEGMENT
              NAME_REF
                IDENT "bar"
          TOKEN_TREE
            L_PAREN "("
            R_PAREN ")"
        R_PAREN ")"
      COMMA ","
      WHITESPACE " "
      CFG_ATTR_META
        CFG_ATTR_KW "cfg_attr"
        L_PAREN "("
        CFG_COMPOSITE
          IDENT "all"
          L_PAREN "("
          CFG_ATOM
            TRUE_KW "true"
          COMMA ","
          WHITESPACE " "
          CFG_ATOM
            IDENT "foo"
            WHITESPACE " "
            EQ "="
            WHITESPACE " "
            STRING "\"bar\""
          R_PAREN ")"
        COMMA ","
        WHITESPACE " "
        KEY_VALUE_META
          PATH
            PATH_SEGMENT
              NAME_REF
                IDENT "baz"
          WHITESPACE " "
          EQ "="
          WHITESPACE " "
          LITERAL
            STRING "\"baz\""
        R_PAREN ")"
      R_PAREN ")"
    R_BRACK "]"
  WHITESPACE "\n"
