Example
Use import to specify how a namespace from one library is used in the scope of another library.
import 'dart:html';
The only required argument to import is a URI specifying the library. For built-in libraries, the URI has the special dart: scheme. For other libraries, you can use a file system path or the package: scheme. The package: scheme specifies libraries provided by a package manager such as the pub tool. For example:
import 'dart:io';
import 'package:mylib/mylib.dart';
import 'package:utils/utils.dart';
