<PackageReference Include="Microsoft.CSharp" Version="4.7.0-preview1.19504.10" />

Microsoft.CSharp.RuntimeBinder.Semantics.KeyPair<Key1, Key2>

struct KeyPair<Key1, Key2> : IEquatable<KeyPair<Key1, Key2>>
namespace Microsoft.CSharp.RuntimeBinder.Semantics { } namespace Microsoft.CSharp.RuntimeBinder.Semantics { }