Bug 202316 [Forms] Add gradient sharing support for FormHeading
bundles/org.eclipse.ui.forms/src/org/eclipse/ui/internal/forms/widgets/FormImages.java
fColor1 = color1;
			fColor2 = color2;
			fRealtheight = realtheight;
			fTheight = theight;
			fMarginHeight = marginHeight;
		}
		
		public boolean equals(Object obj) {
			if (obj instanceof ImageIdentifier) {
				ImageIdentifier id = (ImageIdentifier) obj;
				if (id.fDisplay.equals(fDisplay) && id.fColor1.equals(fColor1) &&
						id.fColor2.equals(fColor2) && id.fRealtheight == fRealtheight &&
						id.fTheight == fTheight && id.fMarginHeight == fMarginHeight)
					return true;
			}
			return false;
		}
		
		public int hashCode() {
			int hash = fDisplay.hashCode();
			hash = hash * 7 + fColor1.hashCode();
			hash = hash * 7 + fColor2.hashCode();
			hash = hash * 7 + new Integer(fRealtheight).hashCode();
			hash = hash * 7 + new Integer(fTheight).hashCode();
			hash = hash * 7 + new Integer(fMarginHeight).hashCode();
			return hash;
		}
	}
	
	private class ImageReference {