code: def clear(self, chunk_size=1000, aggressive=False):
          
          assert self.attached_to_model, \
              '`clear` can only be called on an index attached to the model field'
  
          if aggressive:
              keys = self.get_all_storage_keys()
              with self.model.database.pipeline(transaction=False) as pipe:
                  for key in keys:
                      pipe.delete(key)
                  pipe.execute()
  
          else:
              start = 0
              while True:
                  instances = self.model.collection().sort().instances(skip_exist_test=True)[start:start + chunk_size]
                  for instance in instances:
                      field = instance.get_instance_field(self.field.name)
                      value = field.proxy_get()
                      if value is not None:
                          field.deindex(value, only_index=self)
  
                  if len(instances) < chunk_size:  # not enough data, it means we are done
                      break
  
                  start += chunk_size
docs: Will deindex all the value for the current field
  
          Parameters
          ----------
          chunk_size: int
              Default to 1000, it's the number of instances to load at once if not in aggressive mode.
          aggressive: bool
              Default to ``False``. When ``False``, the actual collection of instances will
              be ran through to deindex all the values.
              But when ``True``, the database keys will be scanned to find keys that matches the
              pattern of the keys used by the index. This is a lot faster and may find forsgotten keys.
              But may also find keys not related to the index.
              Should be set to ``True`` if you are not sure about the already indexed values.
  
          Raises
          ------
          AssertionError
              If called from an index tied to an instance field. It must be called from the model field
  
          Examples
          --------
  
          >>> MyModel.get_field('myfield')._indexes[0].clear()