String.prototype.ununderscore = function () { return this.split('').map(char => char == '_' ? ' ' : char).join(''); };

var makeGetRequest = (url, options) => {
    const headers = typeof options == 'object' ? options.headers : undefined;
    const identifier = typeof options == 'object' ? options.identifier : undefined;
    const request = new XMLHttpRequest();
    return new Promise((resolve, reject) => {
        request.onreadystatechange = () => {
            if (request.readyState !== 4) return;
            if (request.status == 200) {
                let response = request.responseText;
                if (request.getResponseHeader('content-type').split('json').length == 2) {
                    try {
                        response = JSON.parse(request.responseText);
                    }
                    catch (error) {
                        reject({
                            url: url,
                            status: 400,
                            statusText: error.message,
                            raw_response: request.responseText,
                        });
                    }
                }
                identifier == undefined || (response = {identifier: identifier, response: response});
                resolve(response);
            } else {
                reject({
                    url: url,
                    status: request.status,
                    statusText: request.statusText
                });
            }
        };
        request.open('GET', url);
        if (typeof headers == 'object') {
            for (const header in headers) {
                if (headers.hasOwnProperty(header)) {
                    request.setRequestHeader(header, headers[header]);
                } 
            }
        }
        request.send();
    });
};