gocardless/gocardless-pro/lib/Core/ListResponse.php returns an error when requesting Institutions

[petercalvert]

Context: using v4.20.0 in SANDBOX environment, installed through Composer.

Using a snippet taken directly from the docs for listing Institutions as part of a Billing Request.

$client = new \GoCardlessPro\Client(array(
  'access_token' => 'your_access_token_here',
  'environment'  => \GoCardlessPro\Environment::SANDBOX
));

$client->institutions()->list([
  "params" => ["country_code" => "GB"]
]);

This returns an error in vendor/gocardless/gocardless-pro/lib/Core/ListResponse.php line 37, as the returned response doesn't have a meta key. If you were to dump $this->api_response->body, you're returned the Institution dataset, but dumping $this->api_response->body->meta throws an error for Undefined property: stdClass::$meta.