docs: public void addAttachmentFilesForCall(Context context, UUID callId, Map<String, File> imageAttachmentFiles) {
          Validate.notNull(context, "context");
          Validate.notNull(callId, "callId");
          Validate.containsNoNulls(imageAttachmentFiles.values(), "imageAttachmentFiles");
          Validate.containsNoNullOrEmpty(imageAttachmentFiles.keySet(), "imageAttachmentFiles");
  
          addAttachments(context, callId, imageAttachmentFiles, new ProcessAttachment<File>() {
              @Override
              public void processAttachment(File attachment, File outputFile) throws IOException {
                  FileOutputStream outputStream = new FileOutputStream(outputFile);
                  FileInputStream inputStream = null;
                  try {
                      inputStream = new FileInputStream(attachment);
  
                      byte[] buffer = new byte[1024];
                      int len;
                      while ((len = inputStream.read(buffer)) > 0) {
                          outputStream.write(buffer, 0, len);
                      }
                  } finally {
                      Utility.closeQuietly(outputStream);
                      Utility.closeQuietly(inputStream);
                  }
              }
          });
      }