src/OAuth/Services/OAuthService.php
public static function getConfigDefinitions()
    {
        return [
            'apiVersion' => [
                'valid' => ['string'],
                'default' => \DTS\eBaySDK\OAuth\Services\OAuthService::API_VERSION,
                'required' => true
            ],
            'profile' => [
                'valid' => ['string'],
                'fn'    => 'DTS\eBaySDK\applyProfile',
            ],
            'credentials' => [
                'valid'   => ['DTS\eBaySDK\Credentials\CredentialsInterface', 'array', 'callable'],
                'fn'      => 'DTS\eBaySDK\applyCredentials',
                'default' => [CredentialsProvider::class, 'defaultProvider']
            ],
            'debug' => [
                'valid'   => ['bool', 'array'],
                'fn'      => 'DTS\eBaySDK\applyDebug',
                'default' => false
            ],
            'httpHandler' => [
                'valid'   => ['callable'],
                'default' => 'DTS\eBaySDK\defaultHttpHandler'
            ],
            'httpOptions' => [
                'valid'   => ['array'],
                'default' => [
                    'http_errors' => false
                ]
            ],
            'ruName' => [
                'valid'    => ['string'],
                'required' => true
            ],
            'sandbox' => [
                'valid'   => ['bool'],
                'default' => false
            ]
        ];
    }
public static function getConfigDefinitions()
    {
        return [
            'apiVersion' => [
                'valid' => ['string'],
                'default' => \DTS\eBaySDK\OAuth\Services\OAuthService::API_VERSION,
                'required' => true
            ],
            'profile' => [
                'valid' => ['string'],
                'fn'    => 'DTS\eBaySDK\applyProfile',
            ],
            'credentials' => [
                'valid'   => ['DTS\eBaySDK\Credentials\CredentialsInterface', 'array', 'callable'],
                'fn'      => 'DTS\eBaySDK\applyCredentials',
                'default' => [CredentialsProvider::class, 'defaultProvider']
            ],
            'debug' => [
                'valid'   => ['bool', 'array'],
                'fn'      => 'DTS\eBaySDK\applyDebug',
                'default' => false
            ],
            'httpHandler' => [
                'valid'   => ['callable'],
                'default' => 'DTS\eBaySDK\defaultHttpHandler'
            ],
            'httpOptions' => [
                'valid'   => ['array'],
                'default' => [
                    'http_errors' => false
                ]
            ],
            'ruName' => [
                'valid'    => ['string'],
                'required' => true
            ],
            'sandbox' => [
                'valid'   => ['bool'],
                'default' => false
            ]
        ];
    }
Returns definitions for each configuration option that is supported.

@return array An associative array of configuration definitions.