@Override
  public String getId() {
    return id;
  }
Fully resolve the stack. See stack resolution description in the class documentation.
If the stack has a parent, this stack will be merged against its fully resolved parent
if one is specified.Merging applies to all stack state including child service and
configuration modules.  Services may extend a service in another version in the
same stack hierarchy or may explicitly extend a service in a stack in a different
hierarchy.

@param parentModule   not used.  Each stack determines its own parent since stacks don't
                      have containing modules
@param allStacks      all stacks modules contained in the stack definition
@param commonServices all common services specified in the stack definition
@param extensions     all extension modules contained in the stack definition

@throws AmbariException if an exception occurs during stack resolution
ambari-server/src/main/java/org/apache/ambari/server/stack/StackModule.java