docs: protected boolean isSuppressed()
      {
          if (_suppressed == null)
          {
              // we haven't called this method before, so determine the suppressed
              // value and cache it for later calls to this method.
  
              if (isFacet())
              {
                  // facets are always rendered by their parents --> suppressed
                  _suppressed = Boolean.TRUE;
                  return true;
              }
  
              UIComponent component = getComponentInstance();
  
              // Does any parent render its children?
              // (We must determine this first, before calling any isRendered method
              // because rendered properties might reference a data var of a nesting UIData,
              // which is not set at this time, and would cause a VariableResolver error!)
              UIComponent parent = component.getParent();
              while (parent != null)
              {
                  if (parent.getRendersChildren())
                  {
                      // Yes, parent found, that renders children --> suppressed
                      _suppressed = Boolean.TRUE;
                      return true;
                  }
                  parent = parent.getParent();
              }
  
              // does component or any parent has a false rendered attribute?
              while (component != null)
              {
                  if (!component.isRendered())
                  {
                      // Yes, component or any parent must not be rendered --> suppressed
                      _suppressed = Boolean.TRUE;
                      return true;
                  }
                  component = component.getParent();
              }
  
              // else --> not suppressed
              _suppressed = Boolean.FALSE;
          }
          return _suppressed.booleanValue();
      }