docs: protected BodyPart handlePart(MimePart part) throws IOException, MessagingException {
          String contentType = parseContentType(part.getContentType());
  
          if (part.isMimeType("multipart/*")) {
              return handleMultiPart((Multipart) part.getContent());
          } else if (part.isMimeType("text/*")) {
              return handleTextPart(part, contentType);
          } else if (part.isMimeType("image/*")) {
              return handleImageBinaryPart(part, contentType);
          } else if (part.isMimeType("application/*")) {
              return handleApplicationContentPart(part, contentType);
          } else {
              return handleBinaryPart(part, contentType);
          }
      }