code: def get_filter_value(self, filter_name):
          
          if filter_name == 'dhcp-options-id':
              return self.id
          elif filter_name == 'key':
              return list(self._options.keys())
          elif filter_name == 'value':
              values = [item for item in list(self._options.values()) if item]
              return itertools.chain(*values)
          else:
              return super(DHCPOptionsSet, self).get_filter_value(
                  filter_name, 'DescribeDhcpOptions')
docs: API Version 2015-10-01 defines the following filters for DescribeDhcpOptions:
  
          * dhcp-options-id
          * key
          * value
          * tag:key=value
          * tag-key
          * tag-value
  
          Taken from: http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_DescribeDhcpOptions.html