@Test
public void testResolveExceptionLevel_exceptionCode_is_empty() {

    // do setup.
    Exception exception = new SystemException("", "error.");
    // do test.
    ExceptionLevel actualExceptionLevel = testTarget.resolveExceptionLevel(
            exception);
    // do assert.
    ExceptionLevel expectedExceptionLevel = ExceptionLevel.ERROR;
    assertThat(actualExceptionLevel, is(expectedExceptionLevel));
}