@Test
public void getExecutionVariablesTest2() {

    // overloaded variables can be null
    Map<String, String> executionVariables = CommandExecution.getExecutionVariables(ImmutableMap.of("a", "1", "b", "2"),
                                                                                    new CommandExecution(command, 1, 0, null, null));
    assertEquals(ImmutableMap.of("a", "1", "b", "2"), executionVariables);
}