function popTransactionName(pathSegment) {
  const tx = this.tracer.getTransaction()
  if (tx && tx.nameState) {
    tx.nameState.popPath(pathSegment)
  }
}
Pops one or more elements off the transaction naming stack.

- `popTransactionName([pathSegment])`

Ideally it is not necessary to ever provide the `pathSegment` parameter for
this function, but we do not live in an ideal world.

@memberof TransactionShim.prototype
@param {string} [pathSegment]
 Optional. Path segment to pop the stack repeatedly until a segment matching
 `pathSegment` is removed.