The import org.apache.tools cannot be resolved

I am an Eclipse newbie who are trying to learn how to write tasks from
the following tutorial:
http://ant.apache.org/manual/index.html

example code from the tutorial:
import org.apache.tools.ant.Project;

public class HelloWorld {

private Project project;

public void setProject(Project proj) {
project = proj;
}

public void execute() {
String message = project.getProperty("ant.project.name");
project.log("Here is project '" + message + "'.",
Project.MSG_INFO);
}
}

I could not find the org.apache.tools.ant.jar package from the
http://ant.apache.org/ homepage.

How do I get around this "The import org.apache.tools cannot be
resolved" error?

.