try
{
    // Try to get data...
}
catch (WebException ex)
{
    // If the status code == 409.
    var res = ex.Response;
}

Request req = new HttpPost();
Map<String, String> params = new HashMap<String, String>();
params.put("text", text);
params.put("fkey", fkey);
req.setParameters(params);

... new HttpPost();
...
... "text", text
... "fkey", fkey
...

Request req = new HttpPost();
req.setParameters(new ImmutableMap.Builder().put("text", text).put("fkey", fkey).build());

... new HttpPost();
... "text", text .. "fkey", fkey ..

Map<ImmutableKey<Number>, ? extends Collection<? super Vault>> map;