code: protected void setContentStart(String contentStart) {
          if (contentStart == null) {
              contentStart = StringUtils.EMPTY;
          }
          this.contentStart = contentStart;
      }
docs: <p>Sets the content start text.</p>
  
  <p><code>null</code> is accepted, but will be converted to
  an empty String.</p>
  
  @param contentStart  the new content start text