4.x: Remove unused inner class MultiIterable

metrics/api/src/main/java/io/helidon/metrics/api/SystemTagsManagerImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, 2023 Oracle and/or its affiliates.
+ * Copyright (c) 2022, 2024 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,9 +17,7 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -252,59 +250,4 @@ private Optional<String> scopeFromTags(Iterable<Tag> tags) {
                 : Optional.empty();
     }
 
-    static class MultiIterable<T> implements Iterable<T> {
-
-        private final Iterable<T>[] iterables;
-
-        private MultiIterable(Iterable<T>... iterables) {
-            if (iterables.length == 0) {
-                throw new IllegalArgumentException("Must provide at least one Iterable");
-            }
-            this.iterables = iterables;
-        }
-
-        @Override
-        public Iterator<T> iterator() {
-            return new Iterator<T>() {
-
-                private int nextIndex = 0;
-                private Iterator<T> current = nextIterator();
-
-                @Override
-                public boolean hasNext() {
-                    if (current.hasNext()) {
-                        return true;
-                    }
-
-                    current = nextIterator();
-                    return current.hasNext();
-                }
-
-                @Override
-                public T next() {
-                    return current.next();
-                }
-
-                private Iterator<T> nextIterator() {
-                    while (nextIndex < iterables.length) {
-                        Iterator<T> candidateNextIterator = iterables[nextIndex].iterator();
-                        if (candidateNextIterator.hasNext()) {
-                            nextIndex++;
-                            return candidateNextIterator;
-                        }
-                        nextIndex++;
-                    }
-                    return Collections.emptyIterator();
-                }
-            };
-        }
-
-        @Override
-        public void forEach(Consumer<? super T> action) {
-            for (Iterable<T> it : iterables) {
-                it.forEach(action);
-            }
-        }
-    }
-
 }