Bug 176436 Charts Imported from Libraries do not update when libraries change
During a live presentation of BIRT at EclipseCon, we came across a rather embarassing issue. When charts are included in a library, and imported into a report design from a library, any changes to the library instance of the chart do not reflect in the report itself.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/DesignElementHandle.java
/**
	 * Sets the value of a property to a number (BigDecimal).
	 * 
	 * @param propName
	 *            the property name
	 * @param value
	 *            the value to set
	 * @throws SemanticException
	 *             if the property value cannot be converted from a number.
	 */
	public void setNumberProperty( String propName, BigDecimal value )
			throws SemanticException
	{
		setProperty( propName, value );
	}
	/**
	 * Clears the value of a property. Clearing a property removes any value set
	 * for the property on this element. After this, the element will now
	 * inherit the property from its parent element, style, or from the default
	 * value for the property.
	 * 
	 * @param propName
	 *            the name of the property to clear.
	 * @throws SemanticException
	 *             if the property is not defined on this element
	 */
	public void clearProperty( String propName ) throws SemanticException
	{
		setProperty( propName, null );
	}