'Warn if the requested dates is sooner than the commitment date'

@api.onchange('requested_date')
def onchange_requested_date(self):

    if (self.requested_date and self.commitment_date and (self.requested_date < self.commitment_date)):
        return {'warning': {'title': _('Requested    date    is    too    soon!'), 'message': _("The    date    requested    by    the    customer    is    sooner    than    the    commitment    date.    You    may    be    unable    to    honor    the    customer's    request.")}}
