docs: def build(self):
          """
          Builds the query string, which can be used for a search query
  
          :return: the query string
          """
          if self.es_version == '1':
              if len(self.filters) > 0:
                  return {
                      'filtered': {
                          'query': self.query,
                          'filter': {
                              'and': self.filters
                          }
                      }
                  }
              else:
                  return self.query
          else:
              query = {
                  'bool': {
                      'must': self.query
                  }
              }
              if len(self.filters) > 0:
                  query["bool"]["filter"] = self.filters
              return query