Bug 195607 NPE is thrown when calling DimensionHandle:: getAbsoluteValue()
If a DimensionHandle did not set DimensionValue, NPE will thrown when calling DimensionHandle:: getAbsoluteValue().
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/CSSLengthValueHandler.java
.getUnits( ) ) )
		{
			return new DimensionValue( fontSizeValue.getMeasure( )
					* relativeValue.getMeasure( ) / 2, fontSizeValue.getUnits( ) );
		}
		else if ( DesignChoiceConstants.UNITS_PERCENTAGE.equals( relativeValue
				.getUnits( ) ) )
		{
			return new DimensionValue( fontSizeValue.getMeasure( )
					* relativeValue.getMeasure( ) / 100, fontSizeValue
					.getUnits( ) );
		}
		assert false;
		return null;
	}
	/**
	 * Returns whether the given unit is absolute. The absolute unit includes
	 * absolute length unit and pixel unit.
	 * 
	 * @param unit
	 *            the unit to check
	 * @return true if the given unit is absolute
	 */
	static boolean isAbsoluteUnit( String unit )
	{
		return DimensionUtil.isAbsoluteUnit( unit )
				|| DesignChoiceConstants.UNITS_PX.equalsIgnoreCase( unit );
	}
	
}