Bug 138562 Splite extendsexcpetion to seperate sub class
The suggestion is Parent invalid Cycle extends Different type extends Not top level extends
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/elements/OdaDataSource.java
* @see org.eclipse.birt.report.model.core.DesignElement#getPropertyDefns()
	 */
	public List getPropertyDefns( )
	{
		if ( provider != null )
			return provider.getPropertyDefns( );
		return super.getPropertyDefns( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.DesignElement#getPropertyDefn(java.lang.String)
	 */
	public ElementPropertyDefn getPropertyDefn( String propName )
	{
		assert propName != null;
		ElementPropertyDefn propDefn = super.getPropertyDefn( propName );
		if ( propDefn != null )
			return propDefn;
		if ( provider != null )
			return (ElementPropertyDefn) provider.getPropertyDefn( propName );
		return propDefn;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.core.DesignElement#getIntrinsicProperty(java.lang.String)
	 */
	protected Object getIntrinsicProperty( String propName )
	{