@Test(expected = Exception.class) public void key_input_eleneg_throws_Exception() throws Exception { key(-1, 1); }
private int key(Integer element, int digit) throws IllegalArgumentException { return -1; }
RadixSort { private int key(Integer element, int digit) throws IllegalArgumentException { return -1; } }
RadixSort { private int key(Integer element, int digit) throws IllegalArgumentException { return -1; }  }
RadixSort { private int key(Integer element, int digit) throws IllegalArgumentException { return -1; }  void sort(Integer[] elements); }
RadixSort { private int key(Integer element, int digit) throws IllegalArgumentException { return -1; }  void sort(Integer[] elements);  }