Bug 167511 [Block]NPE when using customized IStyleProcessor with Chart Generator and no Chart will be rendered
Use a customized IStyleProcessor with Generator.build() and the chart will not be rendered in UI.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/factory/Generator.java
case StyledComponent.AXIS_LABEL :
				return StyledComponent.PLOT_BACKGROUND_LITERAL;
			case StyledComponent.AXIS_LINE :
				return StyledComponent.PLOT_BACKGROUND_LITERAL;
			case StyledComponent.SERIES_TITLE :
				return StyledComponent.PLOT_BACKGROUND_LITERAL;
			case StyledComponent.SERIES_LABEL :
				return StyledComponent.PLOT_BACKGROUND_LITERAL;
		}
		return null;
	}
	private boolean updateHierarchyStyle( Chart model, StyledComponent type,
			IStyleProcessor processor, SimpleContainer currentContainer )
	{
		SimpleStyle currentStyle = currentContainer.style;
		IStyle newStyle = null;
		if ( currentStyle == null )
		{
			currentContainer.style = new SimpleStyle( processor.getStyle( model,
					type ) );
			currentStyle = currentContainer.style;
		}
		else
		{
			newStyle = processor.getStyle( model, type );
		}
		if ( newStyle != null )
		{
			if ( currentStyle.getFont( ) == null )
			{