Update Psalm to 4.9.2, fix reported issue

composer.json

@@ -18,7 +18,7 @@
         "brick/varexporter": "~0.2.1",
         "php-coveralls/php-coveralls": "^2.2",
         "phpunit/phpunit": "^7.5.15 || ^8.0 || ^9.0",
-        "vimeo/psalm": "4.7.3"
+        "vimeo/psalm": "4.9.2"
     },
     "suggest": {
         "ext-intl": "Required to format Money objects"

src/Exception/UnknownCurrencyException.php

@@ -1,42 +1,42 @@
-<?php
-
-declare(strict_types=1);
-
-namespace Brick\Money\Exception;
-
-/**
- * Exception thrown when attempting to create a Currency from an unknown currency code.
- */
-class UnknownCurrencyException extends MoneyException
-{
-    /**
-     * @param string|int $currencyCode
-     *
-     * @return UnknownCurrencyException
-     */
-    public static function unknownCurrency($currencyCode) : self
-    {
-        return new self('Unknown currency code: ' . $currencyCode);
-    }
-
-    /**
-     * @param string $countryCode
-     *
-     * @return UnknownCurrencyException
-     */
-    public static function noCurrencyForCountry(string $countryCode) : self
-    {
-        return new self('No currency found for country ' . $countryCode);
-    }
-
-    /**
-     * @param string $countryCode
-     * @param array  $currencyCodes
-     *
-     * @return UnknownCurrencyException
-     */
-    public static function noSingleCurrencyForCountry(string $countryCode, array $currencyCodes) : self
-    {
-        return new self('No single currency for country ' . $countryCode . ': ' . implode(', ', $currencyCodes));
-    }
-}
+<?php
+
+declare(strict_types=1);
+
+namespace Brick\Money\Exception;
+
+/**
+ * Exception thrown when attempting to create a Currency from an unknown currency code.
+ */
+class UnknownCurrencyException extends MoneyException
+{
+    /**
+     * @param string|int $currencyCode
+     *
+     * @return UnknownCurrencyException
+     */
+    public static function unknownCurrency($currencyCode) : self
+    {
+        return new self('Unknown currency code: ' . $currencyCode);
+    }
+
+    /**
+     * @param string $countryCode
+     *
+     * @return UnknownCurrencyException
+     */
+    public static function noCurrencyForCountry(string $countryCode) : self
+    {
+        return new self('No currency found for country ' . $countryCode);
+    }
+
+    /**
+     * @param string   $countryCode
+     * @param string[] $currencyCodes
+     *
+     * @return UnknownCurrencyException
+     */
+    public static function noSingleCurrencyForCountry(string $countryCode, array $currencyCodes) : self
+    {
+        return new self('No single currency for country ' . $countryCode . ': ' . implode(', ', $currencyCodes));
+    }
+}