code: public function lookupPostcodeAddresses( $postcode ){
          
          $path = self::PATH_LOOKUP_POSTCODE;
  
          $response = $this->httpGet( $path, [ 'postcode' => $postcode ] );
  
          return Response\AddressList::buildFromResponse( $response );
  
      }
docs: Returns a list of addresses associated with a postcode.
  
  @param $postcode
  @return Response\AddressList