@Test
void shouldCombineTwoErrors()
{

    RuntimeException error1 = new RuntimeException( "Error1" );
    RuntimeException error2Cause = new RuntimeException( "Error2" );
    CompletionException error2 = new CompletionException( error2Cause );
    CompletionException combined = Futures.combineErrors( error1, error2 );
    assertEquals( error1, combined.getCause() );
    assertArrayEquals( new Throwable[]{error2Cause}, combined.getCause().getSuppressed() );
}