Allows the specification of a matching condition for an argument in a protected member setup, rather than a specific argument value. "ItExpr" refers to the argument being matched.

public static class ItExpr

Use this variant of argument matching instead of It for protected setups.

This class allows the setup to match a method invocation with an arbitrary value, with a value in a specified range, or even one that matches a given predicate, or null.

System..::..Object
  Moq.Protected..::..ItExpr