code: def get_query(query_string, search_fields):
      
      query = None # Query to search for every search term        
      terms = normalize_query(query_string)
      for term in terms:
          or_query = None # Query to search for a given term in each field
          for field in search_fields:
              q = Q(**{"%s__%s" % (field[0], field[1]): term})
              if or_query is None:
                  or_query = q
              else:
                  or_query = or_query | q
          if query is None:
              query = or_query
          else:
              query = query & or_query
      return query
docs: Returns a query, that is a combination of Q objects. That combination
      aims to search keywords within a model by testing the given search fields.
      search_fields should be something like: [('title', 'iexact'), ('content', 'icontains'), ]