diff --git a/src/TimeBucket.php b/src/TimeBucket.php
index dbed339..a5fadd1 100644
--- a/src/TimeBucket.php
+++ b/src/TimeBucket.php
@@ -110,9 +110,7 @@ public function count() : int
      */
     public function sliceCount() : int
     {
-        $iter = $this->getIterator(); //Perform this action on a copy of the queue to ensure we don't modify it
-        $iter->setExtractFlags(SplPriorityQueue::EXTR_PRIORITY);
-        return $iter->isEmpty() ? 0 : count(array_unique(iterator_to_array($iter)));
+        return $this->innerQueue->priorityCount();
     }
 
     /**
@@ -167,6 +165,7 @@ public function insert($datum, $priority)
      */
     public function getIterator() : TimeOrderedStorageInterface
     {
+        $this->innerQueue->beforeClone();
         return clone $this->innerQueue;
     }
 
@@ -416,6 +415,7 @@ public function unserialize($data)
      */
     function __clone()
     {
+        $this->innerQueue->beforeClone();
         $this->innerQueue = clone $this->innerQueue;
     }
 }
diff --git a/src/TimeOrderedArray.php b/src/TimeOrderedArray.php
index 57a80da..fa0aa44 100644
--- a/src/TimeOrderedArray.php
+++ b/src/TimeOrderedArray.php
@@ -54,7 +54,7 @@ class TimeOrderedArray implements TimeOrderedStorageInterface {
      *
      * @var ?int|string
      */
-    protected $top = null;
+    protected string|int|null $top = null;
 
     /**
      * Total elements contained in the queue
@@ -94,7 +94,7 @@ public function compare($priority1, $priority2) : int
      * @param mixed $value    Element to insert
      * @param string|int   $priority Priority can be any key acceptable to a PHP array (so int|string)
      */
-    public function insert($value, $priority)
+    public function insert($value, $priority) : void
     {
         if (!array_key_exists($priority, $this->priorities))
         {
@@ -102,7 +102,7 @@ public function insert($value, $priority)
             $newIndex = array_key_last($this->values);
             $this->priorities[$priority] = $newIndex;
             $this->prioritiesUnsorted = true;
-            if (null === $this->top || 1 == $this->compare($priority, $this->top)) {
+            if (null === $this->top || 1 === $this->compare($priority, $this->top)) {
                 $this->top = $priority;
             }
         }
@@ -115,7 +115,7 @@ public function insert($value, $priority)
      *
      * @return mixed
      */
-    public function extract()
+    public function extract() : mixed
     {
         if (!$this->valid()) {
             return false;
@@ -130,12 +130,12 @@ public function extract()
      *
      * @return mixed
      */
-    public function top()
+    public function top() : mixed
     {
         if ($this->isEmpty()) {
             return false;
         }
-        return$this->current();
+        return $this->current();
     }
 
     /**
@@ -235,7 +235,7 @@ public function isEmpty() : bool
      * Set the extraction flag for the queue. Priority / Data / Both
      * @param int $flag
      */
-    public function setExtractFlags(int $flag)
+    public function setExtractFlags(int $flag): void
     {
         $this->mode = $flag;
     }
@@ -248,4 +248,16 @@ public function getExtractFlags() : int
     {
        return $this->mode;
     }
+
+    public function beforeClone() : void {
+        if ($this->prioritiesUnsorted) {
+            uksort($this->priorities, array($this, 'compare'));
+            $this->prioritiesUnsorted = false;
+        }
+    }
+
+    public function priorityCount(): int
+    {
+        return count($this->priorities);
+    }
 }
\ No newline at end of file
diff --git a/src/TimeOrderedQueue.php b/src/TimeOrderedQueue.php
index f841900..b4e7927 100644
--- a/src/TimeOrderedQueue.php
+++ b/src/TimeOrderedQueue.php
@@ -12,6 +12,9 @@
 namespace EdgeTelemetrics\TimeBucket;
 
 use SplPriorityQueue;
+use function array_unique;
+use function count;
+use function iterator_to_array;
 
 class TimeOrderedQueue extends SplPriorityQueue implements TimeOrderedStorageInterface {
     /**
@@ -19,7 +22,7 @@ class TimeOrderedQueue extends SplPriorityQueue implements TimeOrderedStorageInt
      */
     protected int $serial = PHP_INT_MIN;
 
-    public function insert($value, $priority)
+    public function insert($value, $priority) : void
     {
         if (! is_array($priority)) {
             $priority = [$priority, $this->serial++];
@@ -55,15 +58,29 @@ public function current() : mixed
         return $this->fixPriority($extract);
     }
 
-    public function extract()
+    public function extract() : mixed
     {
         $extract = parent::extract();
         return $this->fixPriority($extract);
     }
 
-    public function top()
+    public function top() : mixed
     {
         $extract = parent::top();
         return $this->fixPriority($extract);
     }
+
+    public function beforeClone() : void {
+        //NOOP
+    }
+
+    public function priorityCount(): int
+    {
+        if ($this->isEmpty()) {
+            return 0;
+        }
+        $iter = clone $this;
+        $iter->setExtractFlags(SplPriorityQueue::EXTR_PRIORITY);
+        return count(array_unique(iterator_to_array($iter)));
+    }
 }
\ No newline at end of file
diff --git a/src/TimeOrderedStorageInterface.php b/src/TimeOrderedStorageInterface.php
index 273fce2..4e05f25 100644
--- a/src/TimeOrderedStorageInterface.php
+++ b/src/TimeOrderedStorageInterface.php
@@ -19,14 +19,20 @@
  * @package EdgeTelemetrics\TimeBucket
  */
 interface TimeOrderedStorageInterface extends Iterator, Countable {
-    public function insert($value, $priority);
-    /**
-     * @return int
-     */
-    public function count() : int;
+    public function insert($value, $priority) : void;
+
     public function current() : mixed;
     public function compare($priority1, $priority2) : int;
-    public function extract();
-    public function top();
-    public function isEmpty() : bool;
+    public function extract() : mixed;
+    public function top() : mixed;
+
+    /**
+     * @return bool
+     */
+    public function isEmpty();
+
+    public function priorityCount() : int;
+
+    /** Perform any tasks on parent object prior to clone being called */
+    public function beforeClone() : void;
 }
\ No newline at end of file
diff --git a/tests/timeBucketOrderTest.php b/tests/timeBucketOrderTest.php
index 1fcca56..5797ae1 100644
--- a/tests/timeBucketOrderTest.php
+++ b/tests/timeBucketOrderTest.php
@@ -78,9 +78,14 @@ public function __construct($array)
 
 echo '**** Validate getTimeSlices()' . PHP_EOL;
 $totalDatapoints = 0;
+echo $prevTime = null;
 foreach($bucket->getTimeSlices() as ['time' => $time, 'data' => $data])
 {
     $totalDatapoints += count($data);
+    if ($prevTime !== null && $time < $prevTime) {
+        echo '***ERROR*** Time out of order. ' . PHP_EOL;
+    }
+    $prevTime = $time;
    // echo 'Slice ' . $time . " contains " . count($data) . " datapoints" . PHP_EOL;
 }
 echo 'Bucket contains ' . $totalDatapoints . " datapoints." . PHP_EOL;