public static RotationalStiffness PoundForceFeetPerRadian <T>(this T value) =>
 RotationalStiffness.FromPoundForceFeetPerRadian(Convert.ToDecimal(value));
 public void NumberToPoundForceFeetPerRadianTest() =>
 Assert.Equal(RotationalStiffness.FromPoundForceFeetPerRadian(2), 2.PoundForceFeetPerRadian());