old_contents: from django.contrib import admin
  
  from geotrek.core.models import (PathSource, Stake, Usage, Network, Comfort)
  from geotrek.common.mixins.actions import MergeActionMixin
  
  
  class PathSourceAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('source', 'structure')
      search_fields = ('source', 'structure')
      list_filter = ('structure',)
      merge_field = "source"
  
  
  class StakeAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('stake', 'structure')
      search_fields = ('stake', 'structure')
      list_filter = ('structure',)
      merge_field = "stake"
  
  
  class UsageAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('usage', 'structure')
      search_fields = ('usage', 'structure')
      list_filter = ('structure',)
      merge_field = "usage"
  
  
  class NetworkAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('network', 'structure')
      search_fields = ('network', 'structure')
      list_filter = ('structure',)
      merge_field = "network"
  
  
  class ComfortAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('comfort', 'structure')
      search_fields = ('comfort', 'structure')
      list_filter = ('structure',)
      merge_field = "comfort"
  
  
  admin.site.register(PathSource, PathSourceAdmin)
  admin.site.register(Stake, StakeAdmin)
  admin.site.register(Usage, UsageAdmin)
  admin.site.register(Network, NetworkAdmin)
  admin.site.register(Comfort, ComfortAdmin)
  
new_contents: from django.contrib import admin
  
  from geotrek.core.models import (
      PathSource, Stake, Usage, Network, Comfort,
      CertificationLabel, CertificationStatus
  )
  from geotrek.common.mixins.actions import MergeActionMixin
  
  
  class PathSourceAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('source', 'structure')
      search_fields = ('source', 'structure')
      list_filter = ('structure',)
      merge_field = "source"
  
  
  class StakeAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('stake', 'structure')
      search_fields = ('stake', 'structure')
      list_filter = ('structure',)
      merge_field = "stake"
  
  
  class UsageAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('usage', 'structure')
      search_fields = ('usage', 'structure')
      list_filter = ('structure',)
      merge_field = "usage"
  
  
  class NetworkAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('network', 'structure')
      search_fields = ('network', 'structure')
      list_filter = ('structure',)
      merge_field = "network"
  
  
  class ComfortAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('comfort', 'structure')
      search_fields = ('comfort', 'structure')
      list_filter = ('structure',)
      merge_field = "comfort"
  
  
  class CertificationLabelAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('label', 'structure')
      search_fields = ('label', 'structure')
      list_filter = ('structure',)
      merge_field = "label"
  
  
  class CertificationStatusAdmin(MergeActionMixin, admin.ModelAdmin):
      list_display = ('label', 'structure')
      search_fields = ('label', 'structure')
      list_filter = ('structure',)
      merge_field = "label"
  
  
  admin.site.register(PathSource, PathSourceAdmin)
  admin.site.register(Stake, StakeAdmin)
  admin.site.register(Usage, UsageAdmin)
  admin.site.register(Network, NetworkAdmin)
  admin.site.register(Comfort, ComfortAdmin)
  admin.site.register(CertificationLabel, CertificationLabelAdmin)
  admin.site.register(CertificationStatus, CertificationStatusAdmin)
  
subject: Add admin