Fixed some sonar-reported issues.
diff --git a/utils/misc/src/main/java/org/onlab/graph/AdjacencyListsGraph.java b/utils/misc/src/main/java/org/onlab/graph/AdjacencyListsGraph.java
index a5a1300..e1e0524 100644
--- a/utils/misc/src/main/java/org/onlab/graph/AdjacencyListsGraph.java
+++ b/utils/misc/src/main/java/org/onlab/graph/AdjacencyListsGraph.java
@@ -22,8 +22,6 @@
     private final ImmutableSetMultimap<V, E> sources;
     private final ImmutableSetMultimap<V, E> destinations;
 
-    private final Set<E> noEdges = ImmutableSet.of();
-
     /**
      * Creates a graph comprising of the specified vertexes and edges.
      *
diff --git a/utils/misc/src/main/java/org/onlab/graph/BreadthFirstSearch.java b/utils/misc/src/main/java/org/onlab/graph/BreadthFirstSearch.java
index 2346ff6..c02afea 100644
--- a/utils/misc/src/main/java/org/onlab/graph/BreadthFirstSearch.java
+++ b/utils/misc/src/main/java/org/onlab/graph/BreadthFirstSearch.java
@@ -21,8 +21,8 @@
         result.costs.put(src, 0.0);
         frontier.add(src);
 
-        search:
-        while (!frontier.isEmpty()) {
+        boolean reachedEnd = false;
+        while (!reachedEnd && !frontier.isEmpty()) {
             // Prepare the next frontier.
             Set<V> next = new HashSet<>();
 
@@ -40,10 +40,15 @@
                                             true);
                         // If we have reached our intended destination, bail.
                         if (nextVertex.equals(dst)) {
-                            break search;
+                            reachedEnd = true;
+                            break;
                         }
                         next.add(nextVertex);
                     }
+
+                    if (reachedEnd) {
+                        break;
+                    }
                 }
             }
 
diff --git a/utils/misc/src/main/java/org/onlab/graph/Heap.java b/utils/misc/src/main/java/org/onlab/graph/Heap.java
index da1ef45..21eeb85 100644
--- a/utils/misc/src/main/java/org/onlab/graph/Heap.java
+++ b/utils/misc/src/main/java/org/onlab/graph/Heap.java
@@ -25,9 +25,6 @@
  */
 public class Heap<T> {
 
-    private static final String E_HEAP_READONLY = "Heap iterator is read-only";
-    private static final String E_HEAP_END = "Heap iterator reached end of heap";
-
     private final List<T> data;
     private final Comparator<T> comparator;