Revision: Case-Insensitive String Equality

I made revisions to my method for comparing strings while ignoring case.  This is in light of some good feedback I received.  Here is the updated method:

public static bool AreEqualIgnoreCase(string firstString, string secondString)
{
    // if references match (or both are null), quickly return
    if (firstString == secondString) return true;
    
    // if one is null, return false
    if (firstString == null || secondString == null ) return false;
    
    // with two different string instances, call Equals method 
    return firstString.Equals(secondString,
        StringComparison.InvariantCultureIgnoreCase);
}

With the above method, the following logic applies:

Strings.AreEqualIgnoreCase(null, null) == true;
Strings.AreEqualIgnoreCase(null, "string") == false;
Strings.AreEqualIgnoreCase("string", null) == false;
Strings.AreEqualIgnoreCase("string", "text") == false;
Strings.AreEqualIgnoreCase("string", "STRING") == true;