code: public void setDisplayName(String displayName) {
  
          if (CmsStringUtil.isEmpty(displayName) || (IGNORE_DISPLAY_NAME.equals(displayName))) {
              m_displayName = null;
              setDisplayed(false);
          } else {
              m_displayName = displayName;
              m_displayNameForConfiguration = displayName;
              setDisplayed(true);
          }
      }
docs: Sets the display name. If the given name equals IGNORE_DISPLAY_NAME the field is not displayed.<p>
  
  @param displayName the display name to set