Support for Visual Basic .NET queries containing expressions that use the IsNothing(...) method (rather than the Is Nothing operator) is added via a transformation implemented in the VBInformationIsNothingExpressionTransformer class. The transformation, which is enabled by default, replaces expressions calling the IsNothing method to BinaryExpressions comparing with a null constant.
That way, expressions similar to the following will now produce "normalized" expression trees:
The expression tree created by the transformation is equivalent to that produced by:
For LINQ providers customizing the expression tree preprocessing steps applied by the re-linq front-end, add an instance of the VBInformationIsNothingExpressionTransformer class to the ExpressionTransformationStep.