code: public void cancel() {
  
          if (m_lockActionRecord.getChange() == LockChange.locked) {
              CmsObject cms = A_CmsUI.getCmsObject();
              try {
                  CmsResource res = cms.readResource(m_editId);
                  cms.unlockResource(res);
              } catch (CmsException e) {
                  LOG.warn("Failed to unlock resource " + m_editId.toString(), e);
              }
          }
          CmsAppWorkplaceUi.get().enableGlobalShortcuts();
      }
docs: Cancels the edit process. Unlocks the resource if required.<p>
  
  @see org.opencms.ui.components.I_CmsFilePropertyEditHandler#cancel()