Update state.md

[intsmaze]

Offset is Long type, the default value is null, and executing offset+=1 in Java 1.8.x will throw a NullPointerException

What is the purpose of the change

Offset is Long type, the default value is null, and executing offset+=1 in Java 1.8.x will throw a NullPointerException

Brief change log

• In the CounterSource example, add a default value of 0L for offset.

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)