MetricDeltaOutput
One metric's movement.
delta is null when either side has no figure, which is not the same as
a delta of 0 — render an empty cell rather than "no change", or a contract
whose ARR was never set reads as one that did not move.
- impactType: stringenumrequired
Impact label. 'new' is never returned for contracts.
valuesnewchurnupselldownsellnoChange - currentType: numbernullable
Value now
- deltaType: numbernullable
current - previous; null when either side is absent. For an account-currency metric of a contract in another currency, the terms-currency change converted at today's rate instead, so exchange-rate movement is left out
- previousType: numbernullable
Value at the period start

