Example of lazy loading with Dart.

app.dart

import 'dart:async';

@lazy
import 'big_lib.dart' as big show soManyFunctions;

const lazy = const DeferredLibrary('big', uri: 'big.js');

void main() {
  lazy.load().then((_) {
    big.soManyFunctions();
  });
}

big_lib.dart

library big;

soManyFunctions() {
  print('from big library');
}