code: def search_with_additional_term_string(self, filterstr):
          
          filterstr = "(&{}{})".format(self.filterstr, filterstr)
  
          return self.__class__(
              self.base_dn, self.scope, filterstr, attrlist=self.attrlist
          )
docs: Returns a new search object with filterstr and-ed to the original filter
          string. The caller is responsible for passing in a properly escaped
          string.