protected function httpClient()
    {
        if (null === $this->obj_http_client) {
            $this->obj_http_client = $this->initHttpClient();
        }
        return $this->obj_http_client;
    }
protected function httpClient()
    {
        if (null === $this->obj_http_client) {
            $this->obj_http_client = $this->initHttpClient();
        }
        return $this->obj_http_client;
    }
protected function httpClient ( ) { if ( null === $ this -> obj_http_client ) { $ this -> obj_http_client = $ this -> initHttpClient ( ) ; } return $ this -> obj_http_client ; }
Lazily initialise the HTTP Client when needed. Once.

@return ClientInterface
Lazily initialise the HTTP Client when needed . Once .