ClassConstantAccessor.php

<?php

declare (strict_types=1);
namespace OpenTelemetry\SDK\Common\Util;

use LogicException;
class ClassConstantAccessor {
    public static function requireValue(string $className, string $constantName) {
        $constant = self::getFullName($className, $constantName);
        if (!defined($constant)) {
            throw new LogicException(sprintf('The class "%s" does not have a constant "%s"', $className, $constantName));
        }
        return constant($constant);
    }
    public static function getValue(string $className, string $constantName) {
        $constant = self::getFullName($className, $constantName);
        return defined($constant) ? constant($constant) : null;
    }
    private static function getFullName(string $className, string $constantName) : string {
        return $className . '::' . $constantName;
    }

}