src/Core/OAuth/OAuth2/OAuth2LoginHelper.php
private function generateAuthorizationHeader(){
        $encodedClientIDClientSecrets = base64_encode($this->getClientID() . ':' . $this->getClientSecret());
        $authorizationheader = CoreConstants::OAUTH2_AUTHORIZATION_TYPE . $encodedClientIDClientSecrets;
        return $authorizationheader;
    }
private function generateAuthorizationHeader(){
        $encodedClientIDClientSecrets = base64_encode($this->getClientID() . ':' . $this->getClientSecret());
        $authorizationheader = CoreConstants::OAUTH2_AUTHORIZATION_TYPE . $encodedClientIDClientSecrets;
        return $authorizationheader;
    }
Generate Authorization Header based on Client ID and Client Serect
@return String   The authorization value