Update packages/binary/datastructure/random_map.go

Co-authored-by: Ching-Hua (Vivian) Lin <jkrvivian@gmail.com>

packages/binary/datastructure/random_map.go

@@ -112,7 +112,7 @@ func (rmap *RandomMap) Delete(key interface{}) (result interface{}, exists bool)
 	return
 }
 
-// Size returns the number of of key-value mappings in the map.
+// Size returns the number of key-value mappings in the map.
 func (rmap *RandomMap) Size() (result int) {
 	rmap.mutex.RLock()