new_contents: import sys
  from pymongo import MongoClient
  from elasticsearch import Elasticsearch
  
  def clean_mongo(db,filter,cleanProvider):
      if cleanProvider:
          result = db.providers.delete_one(filter)
          print(result.deleted_count,' document deleted in Mongo provider with ',filter)
      result = db.datasets.delete_many(filter)
      print(result.deleted_count,' documents deleted in Mongo collection datasets with ',filter)
      result = db.series.delete_many(filter)
      print(result.deleted_count,' document deleted in Mongo collection series with ',filter)
  
  def clean_elastic(es,filter):
      res = es.search(index = 'widukind', scroll='1m', search_type='scan', size=1000, body={'_source': 'false','filter': {'term': filter}})
      sid = res['_scroll_id']
      scroll_size = res['hits']['total']
      while (scroll_size > 0):
          res = es.scroll(scroll_id=sid, scroll='1m')
          if len(res['hits']['hits']) == 0:
              break
          sid = res['_scroll_id']
          bulk = []
          for r in res['hits']['hits']:
              bulk.append({'delete': {'_index': str(r['_index']),
                                      '_type': str(r['_type']),
                                      '_id': str(r['_id'])}})
          res1 = es.bulk(body=bulk)
          print(res1)
          
  provider = ''
  datasetCode = ''
  for arg in sys.argv:        
         t = arg.partition('=')
         if t[0].lower() == 'provider':
             provider = t[2]
         elif t[0].lower() == 'dataset':
             datasetCode = t[2]
  
  if not datasetCode and not provider:
      print('Usage:\n  provider=<provider_name>\n  dataset=<datasetCode>\n')
      sys.exit()
  
  if datasetCode and not provider:
      print('ERROR: provider is missing')
      sys.exit()
  
  filter = {'provider': provider}
  cleanProvider = True
  if datasetCode:
      cleanProvider = False
      filter.update({'datasetCode': datasetCode})
  db = MongoClient().widukind
  es = Elasticsearch()
  clean_mongo(db,filter,cleanProvider)
  clean_elastic(es,filter)
  
subject: add utility to remove a provider and/or a dataset