SOURCE_FILE
  FN
    COMMENT "// 2015"
    WHITESPACE "\n"
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "foo"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        WHITESPACE " "
        EXPR_STMT
          MACRO_EXPR
            MACRO_CALL
              PATH
                PATH_SEGMENT
                  NAME_REF
                    IDENT "try"
              BANG "!"
              TOKEN_TREE
                L_PAREN "("
                IDENT "Ok"
                TOKEN_TREE
                  L_PAREN "("
                  TOKEN_TREE
                    L_PAREN "("
                    R_PAREN ")"
                  R_PAREN ")"
                R_PAREN ")"
          SEMICOLON ";"
        WHITESPACE " "
        R_CURLY "}"
  WHITESPACE "\n"
