code: public void addContent(String destSpaceId,
                             String destContentId,
                             String fileChecksum,
                             File file) {
          Map<String, String> properties =
              StorageProviderUtil.createContentProperties(file.getAbsolutePath(), null);
          addContent(destSpaceId,
                     destContentId,
                     fileChecksum,
                     file.length(),
                     getInputStream(file),
                     properties);
      }
docs: This method pushes the content file to the space destSpaceId with the
  content ID destContentId
  
  @param destSpaceId   of content destination
  @param destContentId of content
  @param fileChecksum  MD5 checksum of file or null if not known
  @param file          to add