The MozNetworkStatsData objects represent a chunk of data usage statistics.
It provides the total amount of data received and sent during a given amount of time. The exact amount of time is provided by the MozNetworkStatsManager.sampleRate property. ``
A number representing the number of bytes received at "date" for "sampleRate" seconds.
A number representing the number of bytes sent at "date" for "sampleRate" seconds.
A date representing the time when the number of bytes received and sent were stored.