code: def initialize_processing():
      
  
      need_initialize = False
  
      needed_algorithms = [
          'native:clip',
          'gdal:cliprasterbyextent',
          'native:union',
          'native:intersection'
      ]
  
      if not QgsApplication.processingRegistry().algorithms():
          need_initialize = True
  
      if not need_initialize:
          for needed_algorithm in needed_algorithms:
              if not QgsApplication.processingRegistry().algorithmById(
                      needed_algorithm):
                  need_initialize = True
                  break
  
      if need_initialize:
          QgsApplication.processingRegistry().addProvider(QgsNativeAlgorithms())
          processing.Processing.initialize()
docs: Initializes processing, if it's not already been done