kubernetes/vendor/github.com/emicklei/go-restful/v3/options_filter.go

// OPTIONSFilter is a filter function that inspects the Http Request for the OPTIONS method
// and provides the response with a set of allowed methods for the request URL Path.
// As for any filter, you can also install it for a particular WebService within a Container.
// Note: this filter is not needed when using CrossOriginResourceSharing (for CORS).
func (c *Container) OPTIONSFilter(req *Request, resp *Response, chain *FilterChain) { … }

// OPTIONSFilter is a filter function that inspects the Http Request for the OPTIONS method
// and provides the response with a set of allowed methods for the request URL Path.
// Note: this filter is not needed when using CrossOriginResourceSharing (for CORS).
func OPTIONSFilter() FilterFunction { … }