<PackageReference Include="NUnit" Version="4.3.1" />

PrefixConstraint

public abstract class PrefixConstraint : Constraint
Abstract base class used for prefixes
using System; using System.Runtime.CompilerServices; namespace NUnit.Framework.Constraints { [NullableContext(1)] [Nullable(0)] public abstract class PrefixConstraint : Constraint { protected IConstraint BaseConstraint { get; } protected string DescriptionPrefix { get; } public override string Description => FormatDescription(DescriptionPrefix, BaseConstraint); protected PrefixConstraint(IResolveConstraint baseConstraint, string descriptionPrefix) : base(baseConstraint) { Guard.ArgumentNotNull(baseConstraint, "baseConstraint"); BaseConstraint = baseConstraint.Resolve(); DescriptionPrefix = descriptionPrefix; } internal static string FormatDescription(string descriptionPrefix, IConstraint baseConstraint) { bool flag = (baseConstraint is EqualConstraint || baseConstraint is EqualStringConstraint) ? true : false; bool flag2 = flag; if (!flag2) { Type type = baseConstraint.GetType(); flag2 = (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(EqualNumericConstraint<>)); } return string.Format(flag2 ? "{0} equal to {1}" : "{0} {1}", descriptionPrefix, baseConstraint.Description); } } }