src/vs/platform/contextkey/common/contextkey.ts/ContextKeySmallerEqualsExpr/evaluate
class ContextKeySmallerEqualsExpr:	public evaluate(context: IContext): boolean {
		if (typeof this.value === 'string') {
			return false;
		}
		return (parseFloat(<any>context.getValue(this.key)) <= this.value);
	}