TrigonometricFunctionUtils { public static double atan(final double x) { return Math.atan(x); }  static double acos(final double x); static ComplexNumber acos(final ComplexNumber z); static double acosh(final double x); static ComplexNumber acosh(final ComplexNumber z); static double asin(final double x); static ComplexNumber asin(final ComplexNumber z); static double asinh(final double x); static ComplexNumber asinh(final ComplexNumber z); static double atan(final double x); static ComplexNumber atan(final ComplexNumber z); static double atanh(final double x); static ComplexNumber atanh(final ComplexNumber z); static double cos(final double x); static ComplexNumber cos(final ComplexNumber z); static double cosh(final double x); static ComplexNumber cosh(final ComplexNumber z); static double sin(final double x); static ComplexNumber sin(final ComplexNumber z); static double sinh(final double x); static ComplexNumber sinh(final ComplexNumber z); static double tan(final double x); static ComplexNumber tan(final ComplexNumber z); static double tanh(final double x); static ComplexNumber tanh(final ComplexNumber z);  }
@Test(expectedExceptions = IllegalArgumentException.class) public void testNull5() { TrigonometricFunctionUtils.atan(null); }