events: add store implementation (#1957)

events/stream/memory/options.go

@@ -0,0 +1,18 @@
+package memory
+
+import "github.com/micro/go-micro/v3/store"
+
+// Options which are used to configure the in-memory stream
+type Options struct {
+	Store store.Store
+}
+
+// Option is a function which configures options
+type Option func(o *Options)
+
+// Store sets the store to use
+func Store(s store.Store) Option {
+	return func(o *Options) {
+		o.Store = s
+	}
+}