1 files changed, 23 insertions, 0 deletions
diff --git a/opt.go b/opt.go
new file mode 100644
index 0000000..840a98f
--- /dev/null
+++ b/opt.go
@@ -0,0 +1,23 @@
+package exchange
+
+import "time"
+
+var DefaultTTL = 24 * time.Hour
+
+type Option func(o *options)
+
+type options struct {
+	ttl time.Duration
+}
+
+func parseOpts(opts []Option) options {
+	o := options{DefaultTTL}
+	for i := range opts {
+		opts[i](&o)
+	}
+	return o
+}
+
+func WithTTL(ttl time.Duration) Option {
+	return func(o *options) { o.ttl = ttl }
+}