Bug 281126 [CSS] Illegal state exc from tab-height
If you just type a space in the CSS Editors SWT example you will get traces in the console failing on CSSValue.getFloatValue() for tab-height.
bundles/org.eclipse.e4.ui.css.core/src/org/eclipse/e4/ui/css/core/impl/dom/Measure.java
|| (lexicalUnit == LexicalUnit.SAC_STRING_VALUE)
				|| (lexicalUnit == LexicalUnit.SAC_URI))
			return value.getStringValue();
		
		throw new UnsupportedOperationException("NOT YET IMPLEMENTED");
	}
	
	/*
	 * (non-Javadoc)
	 * @see org.w3c.dom.css.CSSPrimitiveValue#getPrimitiveType()
	 */
	public short getPrimitiveType() {
		switch (value.getLexicalUnitType()) {
		case LexicalUnit.SAC_IDENT:
			return CSS_IDENT;
		case LexicalUnit.SAC_INTEGER:
		case LexicalUnit.SAC_REAL:
			return CSS_NUMBER;
		case LexicalUnit.SAC_URI:
			return CSS_URI;
		case LexicalUnit.SAC_PERCENTAGE:
			return CSS_PERCENTAGE;
		case LexicalUnit.SAC_PIXEL:
			return CSS_PX;
		case LexicalUnit.SAC_CENTIMETER:
			return CSS_CM;
		case LexicalUnit.SAC_EM:
			return CSS_EMS;
		case LexicalUnit.SAC_INCH:
			return CSS_IN;