March 2021 Update

See description in "Foreword to the Leanpub Edition" at www.OnJava8.com

Rewrote "Type Information" Chapter; added missing @Overrides

Also fixed onjava/Range.java
Updated to latest Gradle 6.8.1

Works with Java 8 and newer Java versions

For the updated Leanpub version of the book, see www.OnJava8.com