Bug 153853 [Regression]The bound column names must be unique within the entire table.
Regression case Regression_136421(under org.eclipse.birt.report.tests.model) failed. Expected result: Model will avoid adding a duplicate bound column name within a table.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/elements/ReportItem.java
DATA_SET_PROP );
		if ( dataSetRef == null )
			return null;
		return dataSetRef.getElement( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.DesignElement#validate(org.eclipse.birt.report.model.elements.ReportDesign)
	 */
	public List validate( Module module )
	{
		List list = super.validate( module );
		
		list.addAll( ElementReferenceValidator.getInstance( ).validate( module,
				this, DATA_SET_PROP ) );
		list.addAll( validateStructureList( module, PARAM_BINDINGS_PROP ) );
		return list;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.DesignElement#getStrategy()
	 */
	public PropertySearchStrategy getStrategy( )
	{
		return ReportItemPropSearchStrategy.getInstance( );
	}
}