const koaWetland    = require('koa-wetland');
const wetland       = new Wetland(config);

// [...] any middleware added here will only have wetland exposed after awaiting next
app.use(koaWetland(wetland));
// [...] (any middleware that added here will have wetland exposed.

const koaWetland    = require('koa-wetland');
const wetland       = new Wetland(config);
const KoaSmart      = require('koa-smart');
const app           = new KoaSmart({ /* [...] */ });

// [...]

app.addMiddlewares([
// [...] any middleware here will only have wetland exposed after awaiting next
    koaWetland(wetland),
// [...] (any middleware that goes here will have wetland exposed.
]);