Added comment to describe if statement on createHere

Author: Nyholm

src/Model/SourceLocation.php

@@ -63,6 +63,7 @@ public function __construct($message, $path, $line, array $context = [])
     public static function createHere($message, array $context = [])
     {
         foreach (debug_backtrace(DEBUG_BACKTRACE_PROVIDE_OBJECT, 2) as $trace) {
+            // File is not set if we call from an anonymous context like an array_map function.
             if (isset($trace['file'])) {
                 break;
             }