input: Write a function to load a JSON fixture file, extract properties from it, create Property objects from the properties, and save them to the database. The function should return the number of objects saved to the database. The JSON fixture file should have a "properties" key containing a list of property objects. If the fixture file is not specified, the function should use the default file name "properties.json" and the default folder "models/fixtures". The saved objects count will be printed to the console.
  
  def load_properties_from_fixture(fixture_file='properties.json', fixture_folder='models/fixtures'):
      properties_to_save = []
      base_path = os.path.abspath('.')
      path = os.path.sep.join([base_path, 'app', fixture_folder, fixture_file])
      with open(path) as file_:
          data = json.load(file_)
      properties = data['properties']
      for property_ in properties:
          property_.pop('id')
          properties_to_save.append(Property(**property_))
      Property.objects.insert(properties_to_save)
      return len(properties_to_save)
  
  assert load_properties_from_fixture('properties.json', 'models/fixtures') == 5
  assert load_properties_from_fixture('custom_properties.json', 'fixtures') == 3
  assert load_properties_from_fixture() == 5
output: def load_properties_from_fixture(fixture_file='properties.json', fixture_folder='models/fixtures'):
      properties_to_save = []
      base_path = os.path.abspath('.')
      path = os.path.sep.join([base_path, 'app', fixture_folder, fixture_file])
      with open(path) as file_:
          data = json.load(file_)
      properties = data['properties']
      for property_ in properties:
          property_.pop('id')
          properties_to_save.append(Property(**property_))
      Property.objects.insert(properties_to_save)
      return len(properties_to_save)