original_string: public function addContent(string $content, string $contentType, ?string $charset = null): Message
      {
          $charset = $charset ?: $this->getCharset();
  
          $this->content[] = [
              'content'      => $content,
              'content_type' => $contentType,
              'charset'      => $charset
          ];
  
          return $this;
      }
code: public function addContent(string $content, string $contentType, ?string $charset = null): Message
      {
          $charset = $charset ?: $this->getCharset();
  
          $this->content[] = [
              'content'      => $content,
              'content_type' => $contentType,
              'charset'      => $charset
          ];
  
          return $this;
      }
code_tokens: public function addContent ( string $ content , string $ contentType , ? string $ charset = null ) : Message { $ charset = $ charset ? : $ this -> getCharset ( ) ; $ this -> content [ ] = [ 'content' => $ content , 'content_type' => $ contentType , 'charset' => $ charset ] ; return $ this ; }
docstring: Adds a content part
  
  Example content type: "text/plain" or "text/html"
  
  @param string      $content     The content
  @param string      $contentType The content type
  @param string|null $charset     The character set
  
  @return Message
docstring_tokens: Adds a content part