Bug 198479 NullPointerException when exporting report with a bar chart to PDF
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/internal/executor/dom/DOMReportItemExecutor.java
}
	void setContent( IContent content )
	{
		this.content = content;
	}
	public void close( )
	{
		manager.releaseExecutor( this );
	}
	public IContent execute( )
	{
		childIterator = content.getChildren( ).iterator( );
		return content;
	}
	Iterator childIterator;
	public IReportItemExecutor getNextChild( )
	{
		if ( childIterator.hasNext( ) )
		{
			IContent child = (IContent) childIterator.next( );
			return manager.createExecutor( child );
		}
		return null;
	}
	public boolean hasNextChild( )
	{
		return childIterator.hasNext( );
	}
}