Scale returns the (float64) input value (between inputMin and inputMax) scaled to a value between outputMin and outputMax.

ToProtoStruct converts a Transformations instance to a google.protobuf.Struct.

Primitives for an output this would be the value we send out, this is also the input value (for the output/input apply transformations for output apply units).

PriorityValue is an interface that all pri values must satisfy.