How to use the nifgen.errors.DriverNotInstalledError function in nifgen

Returns the library.Library singleton for nifgen.
    '''
    global _instance
    global _instance_lock

    with _instance_lock:
        if _instance is None:
            try:
                library_type = _get_library_type()
                if library_type == 'windll':
                    ctypes_library = ctypes.WinDLL(_get_library_name())
                else:
                    assert library_type == 'cdll'
                    ctypes_library = ctypes.CDLL(_get_library_name())
            except OSError:
                raise errors.DriverNotInstalledError()
            _instance = _library.Library(ctypes_library)
        return _instance

Returns the library.Library singleton for nifgen.
    '''
    global _instance
    global _instance_lock

    with _instance_lock:
        if _instance is None:
            try:
                library_type = _get_library_type()
                if library_type == 'windll':
                    ctypes_library = ctypes.WinDLL(_get_library_name())
                else:
                    assert library_type == 'cdll'
                    ctypes_library = ctypes.CDLL(_get_library_name())
            except OSError:
                raise errors.DriverNotInstalledError()
            _instance = _library.Library(ctypes_library)
        return _instance