@Nullable
    private static PsiExpression extractLeft(PsiMethodCallExpression call) {
      PsiMethodCallExpression qualifierCall = getQualifierMethodCall(call);
      if (!COLLECTION_STREAM.test(qualifierCall) || ExpressionUtil.isEffectivelyUnqualified(qualifierCall.getMethodExpression())) {
        return null;
      }
      return skipParenthesizedExprDown(qualifierCall.getMethodExpression().getQualifierExpression());
    }
@Nullable
    private static PsiExpression extractLeft(PsiMethodCallExpression call)