SOURCE_FILE
  TYPE_ALIAS
    EXISTENTIAL_KW "existential"
    WHITESPACE " "
    TYPE_KW "type"
    WHITESPACE " "
    NAME
      IDENT "Foo"
    COLON ":"
    WHITESPACE " "
    TYPE_BOUND_LIST
      TYPE_BOUND
        PATH_TYPE
          PATH
            PATH_SEGMENT
              NAME_REF
                IDENT "Fn"
              PARAM_LIST
                L_PAREN "("
                R_PAREN ")"
              WHITESPACE " "
              RET_TYPE
                THIN_ARROW "->"
                WHITESPACE " "
                PATH_TYPE
                  PATH
                    PATH_SEGMENT
                      NAME_REF
                        IDENT "usize"
    SEMICOLON ";"
  WHITESPACE "\n"
