func (f VideoFilter) Append(s string) VideoFilter {
	// if filter is empty, then just set
	if f == "" {
		return VideoFilter(s)
	}

	return VideoFilter(fmt.Sprintf("%s,%s", f, s))
}
// Append returns a VideoFilter appending the given string.
Append returns a VideoFilter appending the given string.
// Append returns a VideoFilter appending the given string .
func (f VideoFilter) Append(s string) VideoFilter {
	if f == "" {
		return VideoFilter(s)
	}
	return VideoFilter(fmt.Sprintf("%s,%s", f, s))
}
func ( f VideoFilter ) Append ( s string ) VideoFilter { if f == " " { return VideoFilter ( s ) } return VideoFilter ( fmt . Sprintf ( " " , f , s ) ) }
Append returns a VideoFilter appending the given string.
Append returns a VideoFilter appending the given string .
// if filter is empty, then just set