Fix downsampling test for slow environment

zenoh/tests/interceptors.rs

@@ -61,7 +61,8 @@ fn downsampling() {
         .unwrap();
 
     let interval = std::time::Duration::from_millis(10);
-    let mut last_send_time = std::time::Instant::now();
+    let start_time = std::time::Instant::now();
+    let mut last_send_time = start_time;
     for i in 0..100 {
         let start_time = last_send_time;
         println!("message {}", i);
@@ -81,6 +82,13 @@ fn downsampling() {
     }
 
     // check result count of queries
-    assert_eq!(*count_r100.lock().unwrap(), 10);
-    assert_eq!(*count_r50.lock().unwrap(), 20);
+    let full_elapsed_time = std::time::Instant::now() - start_time;
+    assert_eq!(
+        *count_r100.lock().unwrap(),
+        full_elapsed_time.as_millis() / 100
+    );
+    assert_eq!(
+        *count_r50.lock().unwrap(),
+        full_elapsed_time.as_millis() / 50
+    );
 }