code: public I_CmsPrincipal lookupPrincipal(CmsRequestContext context, CmsUUID principalId) {
  
          CmsDbContext dbc = m_dbContextFactory.getDbContext(context);
          I_CmsPrincipal result = null;
          try {
              result = m_driverManager.lookupPrincipal(dbc, principalId);
          } finally {
              dbc.clear();
          }
          return result;
      }
docs: Lookup and read the user or group with the given UUID.<p>
  
  @param context the current request context
  @param principalId the UUID of the principal to lookup
  
  @return the principal (group or user) if found, otherwise <code>null</code>