src/Fixer/ReturnNotation/ReturnAssignmentFixer.php
private function isSuperGlobal(Token $token)
    {
        static $superNames = [
            '$_COOKIE' => true,
            '$_ENV' => true,
            '$_FILES' => true,
            '$_GET' => true,
            '$_POST' => true,
            '$_REQUEST' => true,
            '$_SERVER' => true,
            '$_SESSION' => true,
            '$GLOBALS' => true,
        ];

        if (!$token->isGivenKind(T_VARIABLE)) {
            return false;
        }

        return isset($superNames[strtoupper($token->getContent())]);
    }
private function isSuperGlobal(Token $token)
    {
        static $superNames = [
            '$_COOKIE' => true,
            '$_ENV' => true,
            '$_FILES' => true,
            '$_GET' => true,
            '$_POST' => true,
            '$_REQUEST' => true,
            '$_SERVER' => true,
            '$_SESSION' => true,
            '$GLOBALS' => true,
        ];

        if (!$token->isGivenKind(T_VARIABLE)) {
            return false;
        }

        return isset($superNames[strtoupper($token->getContent())]);
    }
@param Token $token

@return bool