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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def create_backend(name: str=None, git_index: GitIndex=None, args: str=None) -> StorageBackend: """Initialize a new StorageBackend by it's name and the specified model registry."""

    if name is None:
        name = config.BACKEND
    if not args:
        args = config.BACKEND_ARGS
    if args:
        try:
            kwargs = dict(p.split("=") for p in args.split(","))
        except:  # flake8: noqa
            raise ValueError("Invalid args") from None
    else:
        kwargs = {}
    if git_index is None:
        git_index = GitIndex()
    kwargs["index"] = git_index
    return __registry__[name](**kwargs)