Function spareFor

spareFor(
safety: SafetySnapshot | undefined,
channel: ChannelRefJson,
): SpareInputJson | undefined
The pre-declared spare input for a channel, or undefined when none is set. The one-tap swap-to-spare action re-patches the strip's source onto this.
Parameters
- safety: SafetySnapshot | undefined
  the session's safety snapshot
- channel: ChannelRefJson
  the channel to look up a spare for
Returns SpareInputJson | undefined
the spare mapping or undefined