When I copy paste example in cargo project got following error, anything more I need to do?

[amber-m-o-r-e]

error[E0433]: failed to resolve: use of undeclared type or module Environment
--> src/main.rs:6:15
|
6 | let env = Environment::inherit().insert("foo", "bar");
| ^^^^^^^^^^^ use of undeclared type or module Environment

error: aborting due to previous error

For more information about this error, try rustc --explain E0433.
error: could not compile test_proj.

To learn more, run the command again with --verbose.