v1.4.0

Added

• get_snmp_state(), the SNMP counterpart to get_ping_state(). Same record,
  same shape: the agent's state, when the device was added, and when the state
  last changed.

  It answers for far fewer devices, and that is the point of the docstring.
  AKiPS pings everything it holds but polls SNMP only where SNMP is
  configured. Measured on one fleet, 5,821 devices of 16,785 appeared here and
  the rest were ICMP only — so a caller assuming the same denominator as the
  ping call reads two thirds of the fleet as broken. Absence means not polled,
  not down.

Documentation

• get_unreachable() records that asking only for what is broken is not
  necessarily the cheap way. On one fleet it took roughly three times as long
  as get_ping_state() while returning 289 times fewer rows. Whether that
  holds elsewhere is unknown and it may be a property of that server's data,
  so the note says to measure rather than to switch — but the opposite is the
  natural assumption, which is why it is written down.