ArangoDB: name must be non-empty

When I open page in browser I am getting:

{"id":"786938997027","name":"users","isSystem":false,"status":3,"type":2,"error":false,"code":200}

When I am sending request from code, I am getting next output:

Response: {"error":true,"code":400,"errorNum":1208,"errorMessage":"name must be non-empty"}

What's wrong?

void foo()
{
    string url = "http://localhost:8529/_db/testdb/_api/collection/users"; 
    import std.experimental.logger;
    globalLogLevel(LogLevel.info);

    Json users;

    requestHTTP(url,
        (scope req) {
            req.method = HTTPMethod.POST; 
        },
        (scope res) {
            logInfo("Response: %s", res.bodyReader.readAllUTF8());
            users = res.bodyReader.readAllUTF8();
        }
    );
}

You need to use GET type of request as @Colonel Thirty Two mentioned. So remove this line:

req.method = HTTPMethod.POST;

or change it to:

req.method = HTTPMethod.GET;