buildQueryString

const buildQueryString = (params) => {
	let parts = [];
	let add = (key, value) => {
		parts.push(encodeURIComponent(key) + '=' + encodeURIComponent(value));
	}
	for (let key in params) {
   		let param = params[key];
   		if (Array.isArray(param)) {
            param.map((value) => {
   				add(key, value);
   			});
   		}
   		else {
   			add(key, param);
   		}
	}
	return '?' + parts.join('&').replace(/%20/g, '+');
}