Deprecated.php: unconditional define() causes fatal error when REQUESTS_SILENCE_PSR0_DEPRECATIONS is already defined

[N-M]

Problem

Deprecated.php defines REQUESTS_SILENCE_PSR0_DEPRECATIONS unconditionally:

define("REQUESTS_SILENCE_PSR0_DEPRECATIONS", true);

If another package or the host application (e.g. WordPress core, which defines this constant in its bundled Requests library) has already defined it before this file is loaded, PHP throws a fatal error:

PHP Fatal error: Constant REQUESTS_SILENCE_PSR0_DEPRECATIONS already defined

Note that Razorpay.php in the same package already guards the constant correctly:

if (!defined('REQUESTS_SILENCE_PSR0_DEPRECATIONS'))
    define('REQUESTS_SILENCE_PSR0_DEPRECATIONS', true);

Deprecated.php should follow the same pattern.

Suggested fix

if (!defined('REQUESTS_SILENCE_PSR0_DEPRECATIONS')) define("REQUESTS_SILENCE_PSR0_DEPRECATIONS", true);

Environment

Reproduced when using razorpay/razorpay-php inside a WordPress plugin. WordPress core defines REQUESTS_SILENCE_PSR0_DEPRECATIONS before the plugin's Composer autoloader runs, causing Deprecated.php to collide on load.