code: public function getCustomSections($strKey=null)
  	{
  		@trigger_error('Using FrontendTemplate::getCustomSections() has been deprecated and will no longer work in Contao 5.0. Use FrontendTemplate::sections() instead.', E_USER_DEPRECATED);
  
  		if ($strKey != '' && !isset($this->positions[$strKey]))
  		{
  			return '';
  		}
  
  		$tag = 'div';
  
  		// Use the section tag for the main column
  		if ($strKey == 'main')
  		{
  			$tag = 'section';
  		}
  
  		$sections = '';
  
  		// Standardize the IDs (thanks to Tsarma) (see #4251)
  		foreach ($this->positions[$strKey] as $sect)
  		{
  			if (isset($this->sections[$sect['id']]))
  			{
  				$sections .= "\n" . '<' . $tag . ' id="' . StringUtil::standardize($sect['id'], true) . '">' . "\n" . '<div class="inside">' . "\n" . $this->sections[$sect['id']] . "\n" . '</div>' . "\n" . '</' . $tag . '>' . "\n";
  			}
  		}
  
  		if ($sections == '')
  		{
  			return '';
  		}
  
  		return '<div class="custom">' . "\n" . $sections . "\n" . '</div>' . "\n";
  	}
docs: Return all custom layout sections
  
  @param string $strKey An optional section name
  
  @return string The section markup
  
  @deprecated Deprecated since Contao 4.0, to be removed in Contao 5.0.
  Use FrontendTemplate::sections() instead.