TraceEvent<E>.pushScalar  constructor 
Creates a TraceEvent for Tracer.pushScalar.
Implementation
const factory TraceEvent.pushScalar(
  TraceKey key,
  double value,
) = ScalarEvent<E>;
Creates a TraceEvent for Tracer.pushScalar.
const factory TraceEvent.pushScalar(
  TraceKey key,
  double value,
) = ScalarEvent<E>;