docs: def search_with_additional_term_string(self, filterstr):
          """
          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.
          """
          filterstr = u'(&%s%s)' % (self.filterstr, filterstr)
  
          return self.__class__(self.base_dn, self.scope, filterstr)