old_contents: from django.contrib import admin
  from .models import Match
  from .models import Tip
  
  def delete_tips(modeladmin, request, queryset):
      for match in queryset:
          tips = Tip.object.filter(match = match)
          for tip in tips:
              tip.score = 0
              tip.scoring_field = ""
              tip.is_score_calculated = False
  delete_tips.delete_tips = "Delete calculated scores for tips for these matches"
              
  class MatchAdmin(admin.ModelAdmin):
      actions = [make_published]
  
  admin.site.register(Match, MatchAdmin)
  admin.site.register(Tip)
  
new_contents: from django.contrib import admin
  from .models import Match
  from .models import Tip
  
  def delete_tips(modeladmin, request, queryset):
      for match in queryset:
          tips = Tip.object.filter(match = match)
          for tip in tips:
              tip.score = 0
              tip.scoring_field = ""
              tip.is_score_calculated = False
  delete_tips.delete_tips = "Delete calculated scores for tips for these matches"
              
  class MatchAdmin(admin.ModelAdmin):
      actions = [delete_tips]
  
  admin.site.register(Match, MatchAdmin)
  admin.site.register(Tip)
  
subject: Add action to zero out tips for given match