code: public function getChannels()
  	{
  		if (!$this->User->isAdmin && !\is_array($this->User->newsletters))
  		{
  			return array();
  		}
  
  		$arrChannels = array();
  		$objChannels = $this->Database->execute("SELECT id, title FROM tl_newsletter_channel ORDER BY title");
  
  		while ($objChannels->next())
  		{
  			if ($this->User->hasAccess($objChannels->id, 'newsletters'))
  			{
  				$arrChannels[$objChannels->id] = $objChannels->title;
  			}
  		}
  
  		return $arrChannels;
  	}
docs: Get all channels and return them as array
  
  @return array