Updating data

You might have already noticed that most getters of a Device return an Optional of some kind. This has two reasons:

• For some fields, you first have to update the device by calling one of the update*() methods. In the Javadocs you can see what update method you have to call for a specific field to update.
• Not all data points are returned by the official API when updating. When you don’t use gas, the P1 meter won’t return data points that are about gas.

The default value for all fields is Optional.empty() (or with another form of Optional, like OptionalInt or OptionalDouble), except for some. These fields are required when initializing the class, so you can always access them. Some of these values are never able to change, for example, host address and port.