<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _parse_write_concern(options):
 """Parse write concern options."""

    concern = options.get('w')
    wtimeout = options.get('wtimeoutms')
    j = options.get('journal')
    fsync = options.get('fsync')
    return WriteConcern(concern, wtimeout, j, fsync)