def METHOD_NAME(filepath):
    """Get filenames."""
    listfiles = os.listdir(filepath)
    binfiles = list(
        f for f in listfiles if "signal" in f and f[-4:] == ".bin" and f[0] != "."
    )
    all_files = {}
    infofiles = list()
    for binfile in binfiles:
        bin_num_str = re.search(r"\d+", binfile).group()
        infofile = "info" + bin_num_str + ".xml"
        infofiles.append(infofile)
        infobjfile = os.path.join(filepath, infofile)
        infobj = parse(infobjfile)
        if len(infobj.getElementsByTagName("EEG")):
            signal_type = "EEG"
        elif len(infobj.getElementsByTagName("PNSData")):
            signal_type = "PNS"
        all_files[signal_type] = {
            "signal": "signal{}.bin".format(bin_num_str),
            "info": infofile,
        }
    if "EEG" not in all_files:
        raise FileNotFoundError(
            "Could not find any EEG data in the %d file%s found in %s:\n%s"
            % (len(infofiles), _pl(infofiles), filepath, "\n".join(infofiles))
        )
    return all_files