<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def write_cache(cache, opts):
    '''
    Write the mount cache file.
    '''
    cache_file = get_cache(opts)

    try:
        _cache = salt.utils.stringutils.to_bytes(
            salt.utils.yaml.safe_dump(cache)
        )
        with salt.utils.files.fopen(cache_file, 'wb+') as fp_:
            fp_.write(_cache)
        return True
    except (IOError, OSError):
        log.error('Failed to cache mounts',
                  exc_info_on_loglevel=logging.DEBUG)
        return False