code: public MediaFile upload(final String mediaName, final File file, final MediaMimeType contentType)
              throws IOException, AppPlatformException {
  
          final String uri = StringUtils.join(new String[]{
                  getUri(),
                  mediaName
          }, '/');        
          client.upload(uri, file, contentType.toString());
  
          final List<MediaFile> mediaFiles = list(client, 0, 25);
          for (final MediaFile mediaFile : mediaFiles) {
              if (StringUtils.equals(mediaFile.getMediaName(), mediaName)) return mediaFile;
          }
          return null;
      }
docs: Uploads media file.
  
  @param mediaName new name of media file
  @param file source file for uploading
  @param contentType MIME type of file or <code>null</code>
  @return new media file object
  @throws IOException unexpected error.
  @throws AppPlatformException unexpected exception.