method_exists

<?php     public function boot()

    {

        if (method_exists($this->provider, 'boot')) {

            return $this->provider->boot();

        }

    }

<?php         $core = $image->getCore();



        if ( ! method_exists($core, 'getImageProperties')) {

            throw new NotSupportedException(

                "Reading Exif data is not supported by this PHP installation."

            );