original_string: protected function filterCssUrlCb(array $m)
      {
          if (mb_stripos($m['url'], 'data:') === 0) {
              return $m[0]; // Don't filter `data:` URIs.
          }
          return $m['url_'].$m['open_bracket'].$m['open_encap'].$this->hook_api->applyFilters('css_url()', $m['url']).$m['close_encap'].$m['close_bracket'];
      }
code: protected function filterCssUrlCb(array $m)
      {
          if (mb_stripos($m['url'], 'data:') === 0) {
              return $m[0]; // Don't filter `data:` URIs.
          }
          return $m['url_'].$m['open_bracket'].$m['open_encap'].$this->hook_api->applyFilters('css_url()', $m['url']).$m['close_encap'].$m['close_bracket'];
      }
code_tokens: protected function filterCssUrlCb ( array $ m ) { if ( mb_stripos ( $ m [ 'url' ] , 'data:' ) === 0 ) { return $ m [ 0 ] ; // Don't filter `data:` URIs. } return $ m [ 'url_' ] . $ m [ 'open_bracket' ] . $ m [ 'open_encap' ] . $ this -> hook_api -> applyFilters ( 'css_url()' , $ m [ 'url' ] ) . $ m [ 'close_encap' ] . $ m [ 'close_bracket' ] ; }
docstring: Callback handler for CSS URL filters.
  
  @since 150821 Adding URL filter support.
  
  @param array $m An array of regex matches.
  
  @return string CSS `url()` resource with with filtered URL.
docstring_tokens: Callback handler for CSS URL filters .