System.Collections.Immutable by Microsoft

<PackageReference Include="System.Collections.Immutable" Version="9.0.7" />

 KeyValuePairExtensions

static class KeyValuePairExtensions
using System.ComponentModel; using System.Runtime.CompilerServices; namespace System.Collections.Generic { internal static class KeyValuePairExtensions { [System.Runtime.CompilerServices.NullableContext(1)] [EditorBrowsable(EditorBrowsableState.Never)] public static void Deconstruct<[System.Runtime.CompilerServices.Nullable(2)] TKey, [System.Runtime.CompilerServices.Nullable(2)] TValue>([System.Runtime.CompilerServices.Nullable(new byte[] { 0, 1, 1 })] this KeyValuePair<TKey, TValue> source, out TKey key, out TValue value) { key = source.Key; value = source.Value; } } }