test: Improve tests for new get_mut() function

.github/workflows/test.yml

@@ -6,6 +6,7 @@ on:
   push:
     branches: [ main ]
   pull_request:
+    branches: [ main ]
 
 jobs:
   clippy:

src/trie.rs

@@ -91,9 +91,10 @@ impl<K: Eq + Ord + Clone, V: Clone> Trie<K, V> {
     /// let another_data = "notintest".bytes();
     /// assert_eq!(t.get_mut(data.clone()), None);
     /// t.insert(data.clone(), 42);
-    ///
-    /// assert_eq!(t.get_mut(data), Some(42).as_mut());
-    /// assert_eq!(t.get(another_data), None);
+    /// if let Some(value) = t.get_mut(data.clone()) {
+    ///   *value += 1;
+    /// }
+    /// assert_eq!(t.get_mut(data), Some(43).as_mut());
     /// ```
     pub fn get_mut<I: Iterator<Item = K>>(&mut self, key: I) -> Option<&mut V> {
         self.find_node_mut(key).and_then(|node| node.get_value_mut())