public async Task MinBy_Null()
{
await Assert.ThrowsAsync <ArgumentNullException>(() => AsyncEnumerableEx.MinByAsync(default(IAsyncEnumerable <int>), x => x).AsTask());
await Assert.ThrowsAsync <ArgumentNullException>(() => AsyncEnumerableEx.MinByAsync(Return42, default(Func <int, int>)).AsTask());
await Assert.ThrowsAsync <ArgumentNullException>(() => AsyncEnumerableEx.MinByAsync(default(IAsyncEnumerable <int>), x => x, Comparer <int> .Default).AsTask());
await Assert.ThrowsAsync <ArgumentNullException>(() => AsyncEnumerableEx.MinByAsync(Return42, default(Func <int, int>), Comparer <int> .Default).AsTask());
await Assert.ThrowsAsync <ArgumentNullException>(() => AsyncEnumerableEx.MinByAsync(default(IAsyncEnumerable <int>), x => x, CancellationToken.None).AsTask());
await Assert.ThrowsAsync <ArgumentNullException>(() => AsyncEnumerableEx.MinByAsync(Return42, default(Func <int, int>), CancellationToken.None).AsTask());
await Assert.ThrowsAsync <ArgumentNullException>(() => AsyncEnumerableEx.MinByAsync(default(IAsyncEnumerable <int>), x => x, Comparer <int> .Default, CancellationToken.None).AsTask());
await Assert.ThrowsAsync <ArgumentNullException>(() => AsyncEnumerableEx.MinByAsync(Return42, default(Func <int, int>), Comparer <int> .Default, CancellationToken.None).AsTask());
}
