Custom pattern for HashSet<T> + Queryable.Contains

Because of this issue in Entity Framework I'm looking for a custom search pattern in C# that tracks occurrences of `hashSet.Contains` in which `hashSet` is a HashSet<T> variable and Contains is Queryable.Contains.

I managed to create a pattern that finds hashSets variables of type “System.Collections.Generic.HashSet<int>” followed by “.Contains” textually, but

• that's too specific (not System.Collections.Generic.HashSet<T> )
• it yields false positives because there are more Contains methods for HashSet.

I didn't manage to create a pattern with these elements:

• a variable of type “System.Collections.Generic.HashSet<T>”
• Queryable.Contains
• (
• a variable of type “T”
• )

Is it possible in the custom pattern editor?