TraceCostBasis
Where the per-Turn cost of the segments comes from (1.57.0): estimate, the Turn quantities re-rated from the price list at read time (1.5.0, ADR 0061); usage_events, the Call's frozen Usage events allocated to its Turns, each stage's per-minute charge by the Turn's share of the minutes and request-priced lines to the Turn that caused them, the remainder on the last Turn, so the Turns sum to the Call's charges (section 3.3).
An enumeration of 2 values.
Values
estimateusage_events