<PackageReference Include="NUnit" Version="4.3.2" />

NUnit.Framework.Is

public abstract class Is
Helper class with properties and methods that supply a number of constraints used in Asserts.
namespace NUnit.Framework { public abstract class Is { public static ConstraintExpression Not { get; } public static ConstraintExpression All { get; } public static NullConstraint Null { get; } public static DefaultConstraint Default { get; } public static TrueConstraint True { get; } public static FalseConstraint False { get; } public static GreaterThanConstraint Positive { get; } public static LessThanConstraint Negative { get; } public static EqualConstraint Zero { get; } public static NaNConstraint NaN { get; } public static EmptyConstraint Empty { get; } public static WhiteSpaceConstraint WhiteSpace { get; } public static UniqueItemsConstraint Unique { get; } public static XmlSerializableConstraint XmlSerializable { get; } public static CollectionOrderedConstraint Ordered { get; } public static EqualConstraint EqualTo(object expected); public static EqualConstraint EqualTo<T>(T expected); public static EqualConstraint EqualTo<[Nullable(2)] T>(IEnumerable<T> expected); public static EqualStringConstraint EqualTo(string expected); public static EqualDateTimeOffsetConstraint EqualTo(DateTimeOffset expected); public static EqualTimeBaseConstraint<DateTime> EqualTo(DateTime expected); public static EqualTimeBaseConstraint<TimeSpan> EqualTo(TimeSpan expected); public static EqualNumericConstraint<double> EqualTo(double expected); public static EqualNumericConstraint<float> EqualTo(float expected); public static EqualNumericConstraint<decimal> EqualTo(decimal expected); public static EqualNumericConstraint<long> EqualTo(long expected); public static EqualNumericConstraint<int> EqualTo(int expected); public static EqualNumericConstraint<short> EqualTo(short expected); public static EqualNumericConstraint<byte> EqualTo(byte expected); public static EqualNumericConstraint<ulong> EqualTo(ulong expected); public static EqualNumericConstraint<uint> EqualTo(uint expected); public static EqualNumericConstraint<ushort> EqualTo(ushort expected); public static EqualNumericConstraint<sbyte> EqualTo(sbyte expected); public static SameAsConstraint SameAs(object expected); public static GreaterThanConstraint GreaterThan(object expected); public static GreaterThanOrEqualConstraint GreaterThanOrEqualTo(object expected); public static GreaterThanOrEqualConstraint AtLeast(object expected); public static LessThanConstraint LessThan(object expected); public static LessThanOrEqualConstraint LessThanOrEqualTo(object expected); public static LessThanOrEqualConstraint AtMost(object expected); public static ExactTypeConstraint TypeOf(Type expectedType); public static ExactTypeConstraint TypeOf<[Nullable(2)] TExpected>(); public static InstanceOfTypeConstraint InstanceOf(Type expectedType); public static InstanceOfTypeConstraint InstanceOf<[Nullable(2)] TExpected>(); public static AssignableFromConstraint AssignableFrom(Type expectedType); public static AssignableFromConstraint AssignableFrom<[Nullable(2)] TExpected>(); public static AssignableToConstraint AssignableTo(Type expectedType); public static AssignableToConstraint AssignableTo<[Nullable(2)] TExpected>(); public static CollectionEquivalentConstraint EquivalentTo(IEnumerable expected); public static CollectionEquivalentConstraint EquivalentTo<[Nullable(2)] T>(IEnumerable<T> expected); public static CollectionSubsetConstraint SubsetOf(IEnumerable expected); public static CollectionSubsetConstraint SubsetOf<[Nullable(2)] T>(IEnumerable<T> expected); public static CollectionSupersetConstraint SupersetOf(IEnumerable expected); public static CollectionSupersetConstraint SupersetOf<[Nullable(2)] T>(IEnumerable<T> expected); public static SamePathConstraint SamePath(string expected); public static SubPathConstraint SubPathOf(string expected); public static SamePathOrUnderConstraint SamePathOrUnder(string expected); public static RangeConstraint InRange(object from, object to); public static AnyOfConstraint AnyOf(params object[] expected); public static AnyOfConstraint AnyOf(ICollection expected); protected Is(); } }