How can I used BeEquivalentTo to make null equivalent to empty?

Question

How can I used BeEquivalentTo to compare ActualObject.Flied=null and ExpectedObject.Filed = String.Empty and get they are equivalent? I am looking for something like

ActualObject.Should().BeEquivalentTo(ExpectedObject,????)

Context:

ActualObject.Flied = null
ExpectedObject.Filed = String.Empty 

I tried:

ActualObject.Should().BeEquivalentTo(ExpectedObject) 

but I get an error:

ActualObject.Name to be <null>, but found ""