Phan\Language\UnionType::internalFunctionSignatureMap PHP Метод

    public static function internalFunctionSignatureMap()
    {
        static $map = [];
        if (!$map) {
            $map_raw = (require __DIR__ . '/Internal/FunctionSignatureMap.php');
            foreach ($map_raw as $key => $value) {
                $map[strtolower($key)] = $value;
            }
        }
        return $map;
    }

 /**
  * Add any functions from the FunctionSignatureMap that aren't
  * defined in this version of PHP to the code base
  *
  * @return void
  */
 private function addUndefinedFunctionSignatures()
 {
     $function_signature_map = UnionType::internalFunctionSignatureMap();
     foreach ($function_signature_map as $function_name => $signature) {
         $fqsen = FullyQualifiedFunctionName::make('\\', $function_name);
         // If we already loaded the function, skip it
         if ($this->hasMethod($fqsen)) {
             continue;
         }
         // Add each method returned for the signature
         foreach (Method::methodListFromSignature($this, $fqsen, $signature) as $method) {
             $this->addMethod($method);
         }
     }
 }