' . do_shortcode($content) . ''; } public function radio_station_handler($attrs) { return '
'; } public function wavesurfer_handler($attrs) { return ''; } public function waveform_handler($attrs) { return ''; } public function circular_spectrum_handler($attrs) { return ''; } public function play_button_handler($attrs) { return ''; } public function equalizer_handler($attrs) { return ''; } public function playlist_handler($attrs, $content) { return '