if (aIID.Equals(nsIEditorStyleSheets::GetIID())) {
if (aIID.Equals(NS_GET_IID(nsIEditorStyleSheets))) {
NS_IMETHODIMP nsHTMLEditor::QueryInterface(REFNSIID aIID, void** aInstancePtr){  if (!aInstancePtr)    return NS_ERROR_NULL_POINTER;   *aInstancePtr = nsnull;    if (aIID.Equals(nsIHTMLEditor::GetIID())) {    *aInstancePtr = NS_STATIC_CAST(nsIHTMLEditor*, this);    NS_ADDREF_THIS();    return NS_OK;  }  if (aIID.Equals(nsIEditorMailSupport::GetIID())) {    *aInstancePtr = NS_STATIC_CAST(nsIEditorMailSupport*, this);    NS_ADDREF_THIS();    return NS_OK;  }  if (aIID.Equals(nsITableEditor::GetIID())) {    *aInstancePtr = NS_STATIC_CAST(nsITableEditor*, this);    NS_ADDREF_THIS();    return NS_OK;  }  if (aIID.Equals(nsIEditorStyleSheets::GetIID())) {    *aInstancePtr = NS_STATIC_CAST(nsIEditorStyleSheets*, this);    NS_ADDREF_THIS();    return NS_OK;  }    return nsEditor::QueryInterface(aIID, aInstancePtr);}