SOURCE_FILE
  FN
    FN_KW "fn"
    WHITESPACE " "
    NAME
      IDENT "test"
    PARAM_LIST
      L_PAREN "("
      R_PAREN ")"
    WHITESPACE " "
    WHERE_CLAUSE
      WHERE_KW "where"
      WHITESPACE " "
      WHERE_PRED
        TUPLE_TYPE
          L_PAREN "("
          PATH_TYPE
            PATH
              PATH_SEGMENT
                NAME_REF
                  IDENT "u64"
          COMMA ","
          WHITESPACE " "
          PATH_TYPE
            PATH
              PATH_SEGMENT
                NAME_REF
                  IDENT "u64"
          R_PAREN ")"
        COLON ":"
        WHITESPACE " "
        TYPE_BOUND_LIST
          TYPE_BOUND
            PATH_TYPE
              PATH
                PATH_SEGMENT
                  NAME_REF
                    IDENT "Foo"
    WHITESPACE " "
    BLOCK_EXPR
      STMT_LIST
        L_CURLY "{"
        R_CURLY "}"
