client/keys.go
func NewKeysAPIWithPrefix(c Client, p string) KeysAPI {
	return &httpKeysAPI{
		client: c,
		prefix: p,
	}
}
func NewKeysAPIWithPrefix(c Client, p string) KeysAPI {
	return &httpKeysAPI{
		client: c,
		prefix: p,
	}
}
// NewKeysAPIWithPrefix acts like NewKeysAPI, but allows the caller
// to provide a custom base URL path. This should only be used in
// very rare cases.