code: protected void validateAttachmentContentData(String receivedContent, String controlContent, String controlContentId) {
          if (ignoreAllWhitespaces) {
              controlContent = StringUtils.trimAllWhitespace(controlContent);
              receivedContent = StringUtils.trimAllWhitespace(receivedContent);
          }
  
          Assert.isTrue(receivedContent.equals(controlContent),
                  "Values not equal for attachment content '"
                          + controlContentId + "', expected '"
                          + controlContent.trim() + "' but was '"
                          + receivedContent.trim() + "'");
      }
docs: Validates content data.
  @param receivedContent
  @param controlContent
  @param controlContentId