DOC: need HOW to use NXWriter documentation about apstools HOT 2 OPEN

templates = [
    ["/entry/full_file_name=", adsimdet.hdf1.full_file_name.get()],
]
md = {"title": "APS POLAR", nxwriter.template_key: json.dumps(templates)}

def outer(detectors, motors, **md):
    _md = {}
    _md.update(md)

    nxwriter.file_name = "polar_templates.hdf5"
    print(f"{md=!r}")
    print(f"{_md=!r}")

    @bpp.subs_decorator(nxwriter.receiver)  # collect the data
    @bpp.stage_decorator(list(detectors) + motors)
    @bpp.run_decorator(md=_md)
    def inner():
        # assume adsimdet has already collected its image file
        yield from bps.null()

    yield from inner()
    print(f"{nxwriter.file_path=!r}")
    print(f"{nxwriter.file_name=!r}")


RE(outer([adsimdet], [m1, m2], **md))

def write_entry(self):
        """Called after stop document has been received."""
        nxentry = super().write_entry()
        print(f"{nxentry=!r}")
        nxinstrument = nxentry["instrument"]
      
        if self.ad_file_name is not None:
            # https://manual.nexusformat.org/classes/base_classes/NXdetector.html
            nxdetector = nxinstrument.create_group("detector")
            nxdetector.attrs["NX_class"] = "NXdetector"
            nxdetector["data"] = h5py.ExternalLink(
                str(self.ad_file_name),
                "/entry/data",  # link to the data group with the image dataset
            )
            nxdetector["data_file"] = adsimdet.hdf1.full_file_name.get()
      
        if self.position_file_name is not None:
            # https://manual.nexusformat.org/classes/base_classes/NXcollection.html
            group = nxinstrument.create_group("fast_positions")
            group.attrs["NX_class"] = "NXcollection"
            group["root"] = h5py.ExternalLink(
                str(self.position_file_name),
                "/",  # link to the root of the file
            )