New - Initialize agent service.

PollingPeriod - Polling period seconds for fetch to agent.

ErrAlreadyExists - When already exists.

ErrAmbientNotFetched - When ambient not fetched.

ErrDefaultAgentRequired - When try turn off last default agent.

ErrNoAgent - When there is no agent.

ErrNotFound - When agent does not exists.

ErrRemoveDefaultAgent - When try remove default agent.

Agent - Store of Agent.

AgentService - Provide Agent calls.

Ambient - Ambient sensor from BME280.