Bug 152430 Key can modify to empty string
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/DataSetParameterHandle.java
private void updateParamBindings( String oldParamName, String newParamName )
	{
		DataSetHandle.DataSetParametersPropertyHandle propHandle = (DataSetHandle.DataSetParametersPropertyHandle) getElementHandle( )
				.getPropertyHandle( getPropertyDefn( ).getName( ) );
		propHandle.updateParamBindings( oldParamName, newParamName );
	}
	/**
	 * Returns the position of this parameter in parameter list.
	 * 
	 * @return the position of this parameter.
	 */
	public Integer getPosition( )
	{
		return (Integer) getProperty( DataSetParameter.POSITION_MEMBER );
	}
	/**
	 * Sets the position of this parameter in parameter list.
	 * 
	 * @param position
	 *            the position to set
	 */
	public void setPosition( Integer position )
	{
		setPropertySilently( DataSetParameter.POSITION_MEMBER, position );
	}
	/**
	 * Whether the parameter is optional.
	 * 
	 * @return whether the parameter is optional
	 */