NUnitString public struct NUnitString A class to allow postponing the actual formatting of interpolated strings. Documentation Code public NUnitString(string message) Initializes a new instance of the NUnitString class. public static NUnitString op_Implicit(FormattableString formattableMessage) Implicit conversion from a FormattableString to a NUnitString. public static NUnitString op_Implicit(string message) Implicit conversion from a String to a NUnitString.