fsmap can't 'get' on simplecache wrapped on adlfs

fs = fsspec.filesystem('simplecache', fs=fsspec.filesystem('az', **kw),)
fsm = fs.get_mapper('/some/where')

In [130]: next(iter(fsm.values()))
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-130-88122b9ca828> in <module>
----> 1 next(iter(fsm.values()))

~\programfiles\miniconda\envs\fixtures-cache\lib\_collections_abc.py in __iter__(self)
    867     def __iter__(self):
    868         for key in self._mapping:
--> 869             yield self._mapping[key]
    870
    871

~\programfiles\miniconda\envs\fixtures-cache\lib\site-packages\fsspec\mapping.py in __getitem__(self, key, default)
    133         k = self._key_to_str(key)
    134         try:
--> 135             result = self.fs.cat(k)
    136         except self.missing_exceptions:
    137             if default is not None:

~\programfiles\miniconda\envs\fixtures-cache\lib\site-packages\fsspec\implementations\cached.py in <lambda>(*args, **kw)
    391             # all the methods defined in this class. Note `open` here, since
    392             # it calls `_open`, but is actually in superclass
--> 393             return lambda *args, **kw: getattr(type(self), item).__get__(self)(
    394                 *args, **kw
    395             )

~\programfiles\miniconda\envs\fixtures-cache\lib\site-packages\fsspec\implementations\cached.py in cat(self, path, recursive, on_error, callback, **kwargs)
    568             fns.append(fn)
    569         if getpaths:
--> 570             self.fs.get(getpaths, storepaths)
    571             self.save_cache()
    572

~\programfiles\miniconda\envs\fixtures-cache\lib\site-packages\fsspec\asyn.py in wrapper(*args, **kwargs)
     86     def wrapper(*args, **kwargs):
     87         self = obj or args[0]
---> 88         return sync(self.loop, func, *args, **kwargs)
     89
     90     return wrapper

~\programfiles\miniconda\envs\fixtures-cache\lib\site-packages\fsspec\asyn.py in sync(loop, func, timeout, *args, **kwargs)
     67         raise FSTimeoutError
     68     if isinstance(result[0], BaseException):
---> 69         raise result[0]
     70     return result[0]
     71

~\programfiles\miniconda\envs\fixtures-cache\lib\site-packages\fsspec\asyn.py in _runner(event, coro, result, timeout)
     23         coro = asyncio.wait_for(coro, timeout=timeout)
     24     try:
---> 25         result[0] = await coro
     26     except Exception as ex:
     27         result[0] = ex

~\programfiles\miniconda\envs\fixtures-cache\lib\site-packages\fsspec\asyn.py in _get(self, rpath, lpath, recursive, callback, **kwargs)
    422         from fsspec.implementations.local import make_path_posix
    423
--> 424         rpath = self._strip_protocol(rpath)
    425         lpath = make_path_posix(lpath)
    426         rpaths = await self._expand_path(rpath, recursive=recursive)

~\programfiles\miniconda\envs\fixtures-cache\lib\site-packages\adlfs\spec.py in _strip_protocol(cls, path)
    454         STORE_SUFFIX = ".dfs.core.windows.net"
    455         logger.debug(f"_strip_protocol for {path}")
--> 456         if not path.startswith(("abfs://", "az://", "abfss://")):
    457             path = path.lstrip("/")
    458             path = "abfs://" + path

AttributeError: 'list' object has no attribute 'startswith'

AzureDataLakeFS is derived from AsyncFileSystem. Somewhere WholeFileCache creates a list of paths to get by the wrapped fs self.fs.get. But AsyncFilesystem's _get is only expecting one path.

Start with the WholeFileCache implementation in fsspec/implementations/cached.py and the AsyncFileSystem _get path in fsspec/asyn.py. Reproduce the simplecache-wrapped AzureDataLakeFS case, then inspect how the wrapped filesystem receives multiple paths. Done means the mapper value lookup completes without the list-path AttributeError; add or update a regression test if the repository identifies a suitable test location.