Core/src/ClientTrait.php
private function configureAuthentication(array $config)
    {
        $config['keyFile'] = $this->getKeyFile($config);
        $this->projectId = $this->detectProjectId($config);

        return $config;
    }
private function configureAuthentication(array $config)
    {
        $config['keyFile'] = $this->getKeyFile($config);
        $this->projectId = $this->detectProjectId($config);

        return $config;
    }
private function configureAuthentication ( array $ config ) { $ config [ 'keyFile' ] = $ this -> getKeyFile ( $ config ) ; $ this -> projectId = $ this -> detectProjectId ( $ config ) ; return $ config ; }
Fetch and validate the keyfile and set the project ID.

@param  array $config
@return array
Fetch and validate the keyfile and set the project ID .