URL template</h3>

<p>A string of the following form:</p>

<pre><code class="javascript">'http://{s}.somedomain.com/blabla/{z}/{x}/{y}.png'</code></pre>

<p><code>{s}</code> means one of the available subdomains (used sequentially to help with browser parallel requests per domain limitation; subdomain values are specified in options; <code>a</code>, <code>b</code> or <code>c</code> by default, can be omitted), <code>{z}</code> &mdash; zoom level, <code>{x}</code> and <code>{y}</code> &mdash; tile coor