Bug 53881 [Colors] Color/Gradient registry should return default values.
There should be default values for when a user does .get() on a bad key.
bundles/org.eclipse.jface/src/org/eclipse/jface/resource/FontRegistry.java
*/
	public Font get(String symbolicName) {
		Assert.isNotNull(symbolicName);
		Object result = stringToFont.get(symbolicName);
		if (result != null)
			return (Font) result;
		result = stringToFontData.get(symbolicName);
		if (result == null)
			return defaultFont();
		 
		
		Font font = createFont(symbolicName, (FontData[]) result);
		
		
		 
		if (font == null)
			return defaultFont();
			
		stringToFont.put(symbolicName, font);
		return font;
	}
	/* (non-Javadoc)
	 * @see org.eclipse.jface.resource.ResourceRegistry#getKeySet()
	 */
	public Set getKeySet() {
	    return Collections.unmodifiableSet(stringToFontData.keySet());
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.jface.resource.ResourceRegistry#hasValueFor(java.lang.String)