How to use the nanopb.nanopb.generator.nanopb_generator.Globals.matched_namemasks function in nanopb

def get_nanopb_suboptions(subdesc, options, name):
    '''Get copy of options, and merge information from subdesc.'''
    new_options = nanopb_pb2.NanoPBOptions()
    new_options.CopyFrom(options)

    if hasattr(subdesc, 'syntax') and subdesc.syntax == "proto3":
        new_options.proto3 = True

    # Handle options defined in a separate file
    dotname = '.'.join(name.parts)
    for namemask, options in Globals.separate_options:
        if fnmatch(dotname, namemask):
            Globals.matched_namemasks.add(namemask)
            new_options.MergeFrom(options)

    # Handle options defined in .proto
    if isinstance(subdesc.options, descriptor.FieldOptions):
        ext_type = nanopb_pb2.nanopb
    elif isinstance(subdesc.options, descriptor.FileOptions):
        ext_type = nanopb_pb2.nanopb_fileopt
    elif isinstance(subdesc.options, descriptor.MessageOptions):
        ext_type = nanopb_pb2.nanopb_msgopt
    elif isinstance(subdesc.options, descriptor.EnumOptions):
        ext_type = nanopb_pb2.nanopb_enumopt
    else:
        raise Exception("Unknown options type")

    if subdesc.options.HasExtension(ext_type):
        ext = subdesc.options.Extensions[ext_type]

# Decide the file names
    noext = os.path.splitext(filename)[0]
    headername = noext + options.extension + options.header_extension
    sourcename = noext + options.extension + options.source_extension
    headerbasename = os.path.basename(headername)

    # List of .proto files that should not be included in the C header file
    # even if they are mentioned in the source .proto.
    excludes = ['nanopb.proto', 'google/protobuf/descriptor.proto'] + options.exclude
    includes = [d for d in f.fdesc.dependency if d not in excludes]

    headerdata = ''.join(f.generate_header(includes, headerbasename, options))
    sourcedata = ''.join(f.generate_source(headerbasename, options))

    # Check if there were any lines in .options that did not match a member
    unmatched = [n for n,o in Globals.separate_options if n not in Globals.matched_namemasks]
    if unmatched and not options.quiet:
        sys.stderr.write("Following patterns in " + f.optfilename + " did not match any fields: "
                         + ', '.join(unmatched) + "\n")
        if not Globals.verbose_options:
            sys.stderr.write("Use  protoc --nanopb-out=-v:.   to see a list of the field names.\n")

    return {'headername': headername, 'headerdata': headerdata,
            'sourcename': sourcename, 'sourcedata': sourcedata}

for p in paths:
        if os.path.isfile(os.path.join(p, optfilename)):
            optfilename = os.path.join(p, optfilename)
            if options.verbose:
                sys.stderr.write('Reading options from ' + optfilename + '\n')
            Globals.separate_options = read_options_file(open(optfilename, "rU"))
            break
    else:
        # If we are given a full filename and it does not exist, give an error.
        # However, don't give error when we automatically look for .options file
        # with the same name as .proto.
        if options.verbose or had_abspath:
            sys.stderr.write('Options file not found: ' + optfilename + '\n')
        Globals.separate_options = []

    Globals.matched_namemasks = set()

    # Parse the file
    file_options = get_nanopb_suboptions(fdesc, toplevel_options, Names([filename]))
    f = ProtoFile(fdesc, file_options)
    f.optfilename = optfilename

    return f