default IStore getRootStore() {
    IStore current = this;
    IStore parent;
    while ((parent = current.getParentStore()) != null) {
      current = parent;
    }
    return current;
  }
Returns the top most store in the hierarchy.

@return the top most store in the hierarchy
@since 2.4
spock-core/src/main/java/org/spockframework/runtime/extension/IStore.java