A bit of safety

matrix.go

@@ -180,6 +180,10 @@ func (c *ByClassifier) enroll() {
 
 func sortMap(unsorted *sync.Map, size int) {
 
+	if size == 0 {
+		size = 1
+	}
+
 	type Myt struct {
 		Name string
 		Num  int64