public void GetCustomPropertyValue()
{
const string propertyName = "SomeProp";
const string expectedValue = "Foo";
claimsIdentity.AddClaim(new Claim(ClaimTypePrefix.CustomProperty + propertyName, expectedValue));
claimsIdentity.AddClaim(new Claim(ClaimTypePrefix.CustomProperty + "OtherProperty", "Bar"));
string value = sut.GetCustomPropertyValue(propertyName);
Assert.AreEqual(expectedValue, value);
}