old_contents: from flask_wtf import Form
  from flask_babel import lazy_gettext as _  # noqa
  from wtforms import StringField, SubmitField, TextAreaField, \
      DateField, SelectField
  from wtforms.validators import InputRequired
  
  
  class VacancyForm(Form):
      title = StringField(_('Title'), validators=[InputRequired(
          message=_('A title is required.'))])
      description = TextAreaField(_('Description'), validators=[InputRequired(
          message=_('A description is required.'))])
      start_date = DateField(_('Start date'), validators=[InputRequired(
          message=_('Start date is required.'))])
      end_date = DateField(_('End date'), validators=[InputRequired(
          message=_('End date is required.'))])
      contract_of_service = SelectField(_('Contract'),
                                        choices=[('voltijd', _('Voltijd')),
                                                 ('deeltijd', _('Deeltijd')),
                                                 ('bijbaan', _('Bijbaan')),
                                                 ('stage', _('Stage'))])
      workload = StringField(_('Workload'), validators=[InputRequired(
          message=_('Workload is required.'))])
      company_id = SelectField(_('Company'), coerce=int)
      submit = SubmitField(_('Submit'))
  
new_contents: from flask_wtf import Form
  from flask_babel import lazy_gettext as _  # noqa
  from wtforms import StringField, SubmitField, TextAreaField, \
      DateField, SelectField
  from wtforms.validators import InputRequired
  
  
  class VacancyForm(Form):
      title = StringField(_('Title'), validators=[InputRequired(
          message=_('A title is required.'))])
      description = TextAreaField(_('Description'), validators=[InputRequired(
          message=_('A description is required.'))])
      start_date = DateField(_('Start date'), validators=[InputRequired(
          message=_('Start date is required.'))])
      end_date = DateField(_('End date'), validators=[InputRequired(
          message=_('End date is required.'))])
      contract_of_service = SelectField(_('Contract'),
                                        choices=[('voltijd', _('Voltijd')),
                                                 ('deeltijd', _('Deeltijd')),
                                                 ('bijbaan', _('Bijbaan')),
                                                 ('stage', _('Stage'))])
      workload = StringField(_('Workload'))
      company_id = SelectField(_('Company'), coerce=int)
      submit = SubmitField(_('Submit'))
  
subject: Make workload optional when editing vacancies