private String privateMethod(String message) {
	return "Input: " + message;
}

@Test
public void privateMethodTest() {

	// 1.Create an instance of the implementation class
	TargetClass targetClass = new TargetClass();

	// 2.Create an instance of a private method
	Method privateMethod = TargetClass.class.getDeclaredMethod("privateMethod", String.class);

	// 3.Allow access to private methods
	privateMethod.setAccessible(true);

	// 4.Pass the implementation class instance and method arguments to the instantiated method
	String actual = (String) privateMethod.invoke(targetClass, "Oh my god.");
	String expected = "Input: Oh my god.";

	// Assert
	assertEquals(expected, actual);
}

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