testIamPermissions method
- TestPermissionsRequest request,
 - String project,
 - String zone,
 - String resource, {
 - String? $fields,
 
Returns permissions that a caller has on the specified resource.
request - The metadata request object.
Request parameters:
project - Project ID for this request.
Value must have pattern
(?:(?:\[-a-z0-9\]{1,63}\.)*(?:\[a-z\](?:\[-a-z0-9\]{0,61}\[a-z0-9\])?):)?(?:\[0-9\]{1,19}|(?:\[a-z0-9\](?:\[-a-z0-9\]{0,61}\[a-z0-9\])?)).
zone - The name of the zone for this request.
Value must have pattern \[a-z\](?:\[-a-z0-9\]{0,61}\[a-z0-9\])?.
resource - Name or id of the resource for this request.
Value must have pattern
\[a-z\](?:\[-a-z0-9\]{0,61}\[a-z0-9\])?|\[1-9\]\[0-9\]{0,19}.
$fields - Selector specifying which fields to include in a partial
response.
Completes with a TestPermissionsResponse.
Completes with a commons.ApiRequestError if the API endpoint returned an error.
If the used http.Client completes with an error when making a REST call,
this method will complete with the same error.
Implementation
async.Future<TestPermissionsResponse> testIamPermissions(
  TestPermissionsRequest request,
  core.String project,
  core.String zone,
  core.String resource, {
  core.String? $fields,
}) async {
  final body_ = convert.json.encode(request);
  final queryParams_ = <core.String, core.List<core.String>>{
    if ($fields != null) 'fields': [$fields],
  };
  final url_ = 'projects/' +
      commons.escapeVariable('$project') +
      '/zones/' +
      commons.escapeVariable('$zone') +
      '/instances/' +
      commons.escapeVariable('$resource') +
      '/testIamPermissions';
  final response_ = await _requester.request(
    url_,
    'POST',
    body: body_,
    queryParams: queryParams_,
  );
  return TestPermissionsResponse.fromJson(
      response_ as core.Map<core.String, core.dynamic>);
}