🚨 Fix getMostCommonName returns ?string

Declaring a `non-empty-list` (with `__construct(private string $stableName, string $value)` proved to be impracticable regarding usage changes.

Author: homersimpsons

src/MappingEntry.php

@@ -7,10 +7,11 @@
 use function array_count_values;
 use function array_key_first;
 use function arsort;
+use function assert;
 
 class MappingEntry
 {
-    /** @var array<string> */
+    /** @var list<string> */
     private array $names = [];
 
     public function __construct(private string $stableName)
@@ -29,6 +30,7 @@ public function getStableName(): string
 
     public function getMostCommonName(): string
     {
+        assert(! empty($this->names));
         $values = array_count_values($this->names);
         arsort($values);