Bug 201017 TopN, TopPercent, BottomPercent filters will lead NPE when the values contains NULL[07]
data/org.eclipse.birt.data.tests/test/org/eclipse/birt/data/engine/aggregation/TotalTest.java
private Date[] dates = new Date[]
                            {
            new Date(1000000L),
            new Date(2000000L),
            new Date(3000000L),
            new Date(4000000L)
                            };
    
    private Date[] dates2 = new Date[]
                            {
            new Date(1000000L),
            new Date(2000000L),
            new Date(2000000L),
            new Date(3000000L),
            new Date(4000000L)
                            };
    
    private String[] str2 = new String[]
                                       {
            "test",
            "string",
            "array",
            "for",
            "aggregation"
                                       };
    
    /*
     * @see TestCase#setUp()
     */
    protected void setUp() throws Exception