typed.go
func (t Typed) FloatMust(key string) float64 {
	f, exists := t.FloatIf(key)
	if exists == false {
		panic("expected float value for " + key)
	}
	return f
}
func (t Typed) FloatMust(key string) float64 {
	f, exists := t.FloatIf(key)
	if exists == false {
		panic("expected float value for " + key)
	}
	return f
}
// Returns an float or panics