original_string: public function sendLetter( $templateId, array $personalisation = array(), $reference = '' ){
  
          $payload = $this->buildPayload( 'letter', '', $templateId, $personalisation, $reference );
  
          return $this->httpPost(
              self::PATH_NOTIFICATION_SEND_LETTER,
              $payload
          );
  
      }
code: public function sendLetter( $templateId, array $personalisation = array(), $reference = '' ){
  
          $payload = $this->buildPayload( 'letter', '', $templateId, $personalisation, $reference );
  
          return $this->httpPost(
              self::PATH_NOTIFICATION_SEND_LETTER,
              $payload
          );
  
      }
code_tokens: public function sendLetter ( $ templateId , array $ personalisation = array ( ) , $ reference = '' ) { $ payload = $ this -> buildPayload ( 'letter' , '' , $ templateId , $ personalisation , $ reference ) ; return $ this -> httpPost ( self :: PATH_NOTIFICATION_SEND_LETTER , $ payload ) ; }
docstring: Send a Letter
  
  @param string    $templateId
  @param array     $personalisation
  @param string    $reference
  
  @return array
docstring_tokens: Send a Letter