@RequiresSession
  public StackEntity find(StackId stackId) {
    return find(stackId.getStackName(), stackId.getStackVersion());
  }
Gets the stack that matches the specified stack ID by name and version.

@param stackId
         the stack ID to find (not {@code null}).
@return the stack matching the specified name and version or {@code null}
        if none.
ambari-server/src/main/java/org/apache/ambari/server/orm/dao/StackDAO.java