Fix issue with voider attempting to batch insert an empty array when no matching statements found

Author: ht2

app/locker/repository/Query/EloquentQueryRepository.php

@@ -149,7 +149,11 @@ public function void(array $match, array $opts) {
 
     $opts['authority'] = json_decode(json_encode($opts['client']['authority']));
 
-    return (new StatementsRepo())->store(json_decode(json_encode($statements)), [], $opts);
+    if( count($statements) > 0 ){
+      return (new StatementsRepo())->store(json_decode(json_encode($statements)), [], $opts);      
+    } else {
+      return [];
+    }
   }
 
   /**

app/locker/repository/Statement/EloquentInserter.php

@@ -47,7 +47,7 @@ private function checkForConflict(\stdClass $statement, StoreOptions $opts) {
    * @param \stdClass $statement_y
    * @throws Exceptions\Conflict
    */
-  private function compareForConflict(\stdClass $statement_x, \stdClass $statement_y) {
+  public function compareForConflict(\stdClass $statement_x, \stdClass $statement_y) {
     $matchable_x = $this->matchableStatement($statement_x);
     $matchable_y = $this->matchableStatement($statement_y);
     if ($matchable_x != $matchable_y) {