old_contents: from django import template
  from django.urls import reverse
  
  
  register = template.Library()
  
  
  @register.simple_tag
  def image(img, **kwargs):
      # Convert the kwargs to an appropriate string
      options = []
      for key, value in kwargs.items():
          options.append('{key},{value}'.format(key=key, value=value))
  
      return reverse('rszio_image', kwargs={
          'options': ';'.join(options),
          'path': img,
      })
  
new_contents: from django import template
  from django.conf import settings
  from django.urls import reverse
  
  
  register = template.Library()
  
  
  @register.simple_tag
  def image(img, **kwargs):
      if not img:
          if settings.DEBUG:
              raise ValueError('No image path defined')
          return ''
  
      # Convert the kwargs to an appropriate string
      options = []
      for key, value in kwargs.items():
          options.append('{key},{value}'.format(key=key, value=value))
  
      return reverse('rszio_image', kwargs={
          'options': ';'.join(options),
          'path': img,
      })
  
subject: Raise ValueError when no path and DEBUG