Top 20 NuGet codecontract Packages

Provides performant guard functionality for methods to throw exceptions
Useful functionality for .NET applications.
This library provides guard clauses that could be used to guard against not expected values. It provides conditions for objects, strings, numerics, datatime and enumerables. It is possible to configure which exception should be thrown.
Confidence is an easy to read and debug fluent argument/condition checker in C# with code contracts syntax supported.