code: protected boolean fillAttachmentList(@NonNull Context context, @NonNull String reportText, @NonNull List<Uri> attachments) {
          final InstanceCreator instanceCreator = new InstanceCreator();
          attachments.addAll(instanceCreator.create(config.attachmentUriProvider(), DefaultAttachmentProvider::new).getAttachments(context, config));
          if (mailConfig.reportAsFile()) {
              final Uri report = createAttachmentFromString(context, mailConfig.reportFileName(), reportText);
              if (report != null) {
                  attachments.add(report);
                  return true;
              }
          }
          return false;
      }
docs: Adds all attachment uris into the given list
  
  @param context     a context
  @param reportText        the report content
  @param attachments the target list
  @return if the attachments contain the content