original_string: public function getPdf($id = '')
  	{
  		$id = $id ? : $this->attributes[$this->primary_column];
  		return $this->request('GET', sprintf('%s/%s', $this->getUrl(), $id), array(), "", "pdf");
  	}
code: public function getPdf($id = '')
  	{
  		$id = $id ? : $this->attributes[$this->primary_column];
  		return $this->request('GET', sprintf('%s/%s', $this->getUrl(), $id), array(), "", "pdf");
  	}
code_tokens: public function getPdf ( $ id = '' ) { $ id = $ id ? : $ this -> attributes [ $ this -> primary_column ] ; return $ this -> request ( 'GET' , sprintf ( '%s/%s' , $ this -> getUrl ( ) , $ id ) , array ( ) , "" , "pdf" ) ; }
docstring: Retrieves a PDF file of an invoice
  
  @return mixed
docstring_tokens: Retrieves a PDF file of an invoice