Bug 150899 Cannot bind data values to chart series, which causes chart preview fail.
How to reproduce it? 1. Create a new chart, bind it with valid data set. 2. Assign the valid data values to category series and value series. Current result: 1. There is no chart live preview in chart builder. It still uses the default sample data. 2. Preview, dataset invalid exception is thrown out. Investigation: It is perhaps caused by ResultSetWrapper.java. There is no initializeMeta( ) in the Constructor.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/internal/datafeed/ResultSetWrapper.java
}
	/**
	 * Compares two objects of the same data type
	 * 
	 * @param a
	 *            Object one
	 * @param b
	 *            Object two
	 * 
	 * @return The result of the comparison
	 */
	public static int compareObjects( Object a, Object b )
	{
		
		if ( a == null && b == null )
		{
			return 0;
		}
		
		else if ( a == null && b != null )
		{
			return -1;
		}
		
		else if ( a != null && b == null )
		{
			return 1;
		}
		else if ( a instanceof String )
		{