Commented Unassigned: Collection should contain other collection behaving unexpectedly [12495]

I want to assert that a collection of simple objects includes a smaller collection of the same object type. For some reason actualCollection.Should().Contain(expectedCollection) is failing with a message that shows all of the expected objects are in the actual collection but it's claiming that they aren't.

Here's the assertion failure output I'm getting:
```
Expected collection {
ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "custom"
percentage = 0.333333333333333
},

ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "friends"
percentage = 0
},

ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "friends of friends"
percentage = 0.333333333333333
},

ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "only me"
percentage = 0
},

ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "public"
percentage = 0.333333333333333
}} to contain {

ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "custom"
percentage = 0.333333333333333
},

ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "friends of friends"
percentage = 0.333333333333333
},

ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "public"
percentage = 0.333333333333333
}}, but could not find {

ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "custom"
percentage = 0.333333333333333
},

ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "friends of friends"
percentage = 0.333333333333333
},

ActivityServiceTest.DataTypes.SocialItemSummary
{
category = "public"
percentage = 0.333333333333333
}}
```
Comments: I understand you're reasoning, but .NET itself relies on Equals() for all comparisons. If your object doesn't override the default Equals() provided by Object, you'll end up with reference equality. To support 'structural equality', FA has a specialized API for comparing (collections of) objects. You can read more about that in my blog post http://www.dennisdoomen.net/2012/09/asserting-object-graph-equivalence.html. In the future I might consider using that same engine for the normal collection methods as well, but I'm quite sure most users prefer the current behavior in most cases.