old_contents: from django.contrib.contenttypes.models import ContentType
  
  
  # USEFUL FUNCTIONS FOR FLUENT CONTENTS #############################################################
  
  # Fluent Contents Helper Functions #################################################################
  def create_content_instance(content_plugin_class, page, placeholder_name='main', **kwargs):
      """
      Creates a content instance from a content plugin class.
  
      :param content_plugin_class: The class of the content plugin.
      :param page: The fluent_page instance to create the content
      instance one.
      :param placeholder_name: The placeholder name defined in the
      template. [DEFAULT: main]
      :param kwargs: Additional keyword arguments to be used in the
      content instance creation.
      :return: The content instance created.
      """
      # Get the placeholders that are currently available for the slot.
      placeholders = page.get_placeholder_by_slot(placeholder_name)
  
      # If a placeholder exists for the placeholder_name use the first one provided otherwise create
      # a new placeholder instance.
      if placeholders.exists():
          placeholder = placeholders[0]
      else:
          placeholder = page.create_placeholder(placeholder_name)
  
      # Obtain the content type for the page instance class.
      ct = ContentType.objects.get_for_model(type(page))
  
      # Create the actual plugin instance.
      content_instance = content_plugin_class.objects.create(
          parent_type=ct,
          parent_id=page.id,
          placeholder=placeholder,
          **kwargs
      )
      return content_instance
  
  # END Fluent Contents Helper Functions #############################################################
  
new_contents: from django.contrib.contenttypes.models import ContentType
  
  
  # USEFUL FUNCTIONS FOR FLUENT CONTENTS #############################################################
  
  # Fluent Contents Helper Functions #################################################################
  def create_content_instance(content_plugin_class, test_page, placeholder_name='main', **kwargs):
      """
      Creates a content instance from a content plugin class.
  
      :param content_plugin_class: The class of the content plugin.
      :param test_page: The fluent_page instance to create the content
      instance one.
      :param placeholder_name: The placeholder name defined in the
      template. [DEFAULT: main]
      :param kwargs: Additional keyword arguments to be used in the
      content instance creation.
      :return: The content instance created.
      """
      # Get the placeholders that are currently available for the slot.
      placeholders = test_page.get_placeholder_by_slot(placeholder_name)
  
      # If a placeholder exists for the placeholder_name use the first one provided otherwise create
      # a new placeholder instance.
      if placeholders.exists():
          placeholder = placeholders[0]
      else:
          placeholder = test_page.create_placeholder(placeholder_name)
  
      # Obtain the content type for the page instance class.
      ct = ContentType.objects.get_for_model(type(test_page))
  
      # Create the actual plugin instance.
      content_instance = content_plugin_class.objects.create(
          parent_type=ct,
          parent_id=test_page.id,
          placeholder=placeholder,
          **kwargs
      )
      return content_instance
  
  # END Fluent Contents Helper Functions #############################################################
  
subject: Change argument name to stop probable name clash.