old_contents: from datetime import datetime
  from django.utils.translation import ugettext_lazy as _
  from django.forms.widgets import Select
  
  
  class YearSelect(Select):
      label = _('Any year')
  
      def __init__(self, *args, **kwargs):
          kwargs['choices'] = self._get_choices()
          super(YearSelect, self).__init__(*args, **kwargs)
  
      def _get_choices(self):
          years_range = [(-1, self.label)]
          years_range += [(year, year) for year in self.get_years()]
          return years_range
  
      def get_years(self):
          return range(datetime.today().year, 1979, -1)
  
      def render_options(self, *args, **kwargs):
          """Refresh choices each time the form is rendered.
          (Prevents from having to restart the application on 1st of January
           to see current year for example)
          """
          self.choices = self._get_choices()
          return super(YearSelect, self).render_options(*args, **kwargs)
  
  
  class ValueSelect(Select):
      label = _('Any value')
  
      def __init__(self, *args, **kwargs):
          kwargs['choices'] = self._get_choices()
          super(ValueSelect, self).__init__(*args, **kwargs)
  
      def _get_choices(self):
          values_range = [(-1, self.label)]
          values_range += [(value, value) for value in self.get_values()]
          return values_range
  
      def get_values(self):
          """
          Must be overridden
          """
          return []
  
      def render_options(self, *args, **kwargs):
          """Refresh choices each time the form is rendered.
          (Prevents from having to restart the application on 1st of January
           to see current year for example)
          """
          self.choices = self._get_choices()
          return super(ValueSelect, self).render_options(*args, **kwargs)
  
new_contents: from datetime import datetime
  from django.utils.translation import ugettext_lazy as _
  from django.forms.widgets import Select
  
  
  class YearSelect(Select):
      label = _('Any year')
  
      def __init__(self, *args, **kwargs):
          kwargs['choices'] = self._get_choices()
          super(YearSelect, self).__init__(*args, **kwargs)
  
      def _get_choices(self):
          years_range = [(-1, self.label)]
          years_range += [(year, year) for year in self.get_years()]
          return list(set(years_range))
  
      def get_years(self):
          return range(datetime.today().year, 1979, -1)
  
      def render_options(self, *args, **kwargs):
          """Refresh choices each time the form is rendered.
          (Prevents from having to restart the application on 1st of January
           to see current year for example)
          """
          self.choices = self._get_choices()
          return super(YearSelect, self).render_options(*args, **kwargs)
  
  
  class ValueSelect(Select):
      label = _('Any value')
  
      def __init__(self, *args, **kwargs):
          kwargs['choices'] = self._get_choices()
          super(ValueSelect, self).__init__(*args, **kwargs)
  
      def _get_choices(self):
          values_range = [(-1, self.label)]
          values_range += [(value, value) for value in self.get_values()]
          return values_range
  
      def get_values(self):
          """
          Must be overridden
          """
          return []
  
      def render_options(self, *args, **kwargs):
          """Refresh choices each time the form is rendered.
          (Prevents from having to restart the application on 1st of January
           to see current year for example)
          """
          self.choices = self._get_choices()
          return super(ValueSelect, self).render_options(*args, **kwargs)
  
subject: Fix duplicate implantation year