MINOR: Remove Dead Code from PathTrie (elastic#33280)

* The array size checks are redundant since the array sizes
are checked earlier in those methods too
* The removed methods are just not used anywhere

server/src/main/java/org/elasticsearch/common/path/PathTrie.java

@@ -104,24 +104,12 @@ public void updateKeyWithNamedWildcard(String key) {
             namedWildcard = key.substring(key.indexOf('{') + 1, key.indexOf('}'));
         }
 
-        public boolean isWildcard() {
-            return isWildcard;
-        }
-
-        public synchronized void addChild(TrieNode child) {
-            addInnerChild(child.key, child);
-        }
-
         private void addInnerChild(String key, TrieNode child) {
             Map<String, TrieNode> newChildren = new HashMap<>(children);
             newChildren.put(key, child);
             children = unmodifiableMap(newChildren);
         }
 
-        public TrieNode getChild(String key) {
-            return children.get(key);
-        }
-
         public synchronized void insert(String[] path, int index, T value) {
             if (index >= path.length)
                 return;
@@ -302,7 +290,7 @@ public void insert(String path, T value) {
         }
         int index = 0;
         // Supports initial delimiter.
-        if (strings.length > 0 && strings[0].isEmpty()) {
+        if (strings[0].isEmpty()) {
             index = 1;
         }
         root.insert(strings, index, value);
@@ -327,7 +315,7 @@ public void insertOrUpdate(String path, T value, BiFunction<T, T, T> updater) {
         }
         int index = 0;
         // Supports initial delimiter.
-        if (strings.length > 0 && strings[0].isEmpty()) {
+        if (strings[0].isEmpty()) {
             index = 1;
         }
         root.insertOrUpdate(strings, index, value, updater);
@@ -352,7 +340,7 @@ public T retrieve(String path, Map<String, String> params, TrieMatchingMode trie
         int index = 0;
 
         // Supports initial delimiter.
-        if (strings.length > 0 && strings[0].isEmpty()) {
+        if (strings[0].isEmpty()) {
             index = 1;
         }