Add when to write method

core/logs/log_test.go

@@ -25,4 +25,9 @@ func TestBeeLoggerDelLogger(t *testing.T) {
 	prefix := "My-Cus"
 	l := GetLogger(prefix)
 	assert.NotNil(t, l)
+	l.Print("hello")
+
+	GetLogger().Print("hello")
+	SetPrefix("aaa")
+	Info("hello")
 }