tagOptions is the string following a comma in a struct field's "json" tag, or the empty string. It does not include the leading comma.
type Options string
func New(tagName string, st reflect.StructTag) Options
func (o Options) Contains(optionName string) bool
Contains reports whether a comma-separated list of options contains a particular substr flag. substr must be surrounded by a string boundary or commas.
func (o Options) Equals(val string) bool
Contains reports whether a comma-separated list of options contains a particular substr flag. substr must be surrounded by a string boundary or commas.
func (o Options) IsEmpty() bool
func (o Options) Values() []string