mIsDone = PR_FALSE; if (mFirst == mCurNode) return NS_OK; mCurNode = mFirst; return NS_OK;
return PositionAt(mFirst);
nsresult nsContentIterator::First(){  if (!mFirst)     return NS_ERROR_FAILURE;  mIsDone = PR_FALSE;  if (mFirst == mCurNode)     return NS_OK;  mCurNode = mFirst;  return NS_OK;}