nsGenericContainerElement::RemoveChild(nsIDOMNode* aOldChild, nsIDOMNode** aReturn) { nsIContent* content = nsnull; *aReturn = nsnull;  if (nsnull == aOldChild) { return NS_ERROR_NULL_POINTER;
NS_IMETHOD RemoveChild(nsIDOMNode* aOldChild, nsIDOMNode** aReturn) { return doRemoveChild(this, aOldChild, aReturn);
nsGenericContainerElement::RemoveChild(nsIDOMNode* aOldChild,                                        nsIDOMNode** aReturn){  nsIContent* content = nsnull;  *aReturn = nsnull;  if (nsnull == aOldChild) {    return NS_ERROR_NULL_POINTER;  }  nsresult res = aOldChild->QueryInterface(kIContentIID, (void**)&content);  NS_ASSERTION(NS_OK == res, "Must be an nsIContent");  if (NS_OK == res) {    PRInt32 pos;    IndexOf(content, pos);    if (pos >= 0) {      res = RemoveChildAt(pos, PR_TRUE);      *aReturn = aOldChild;      NS_ADDREF(aOldChild);    }    else {      res = NS_ERROR_DOM_NOT_FOUND_ERR;    }    NS_RELEASE(content);  }  else {    res = NS_ERROR_DOM_HIERARCHY_REQUEST_ERR;  }  return res;}