input: Write a function to load a JSON fixture file, extract properties from it, create Property objects from the properties, save them to the database, and return the number of objects saved. The function should take a fixture file and fixture folder as command line arguments, and print the number of saved objects to the console.
  
  assert main('/path/to/base')==5
  assert main('/path/to/empty')==0
  assert main('/path/to/error')==0
output: def main(fixture_folder):
      import json
      import os
      from myapp.models import Property
      from django.core.management import call_command
  
      fixture_file = os.path.join(fixture_folder, 'fixture.json')
      if not os.path.exists(fixture_file):
          return 0
  
      with open(fixture_file, 'r') as f:
          data = json.load(f)
  
      properties = data.get('properties', [])
      Property.objects.bulk_create([Property(**prop) for prop in properties])
  
      return len(properties)