code: func (jst *Tracer) CaptureStart(from common.Address, to common.Address, create bool, input []byte, gas uint64, value *big.Int) error {
  	jst.ctx["type"] = "CALL"
  	if create {
  		jst.ctx["type"] = "CREATE"
  	}
  	jst.ctx["from"] = from
  	jst.ctx["to"] = to
  	jst.ctx["input"] = input
  	jst.ctx["gas"] = gas
  	jst.ctx["value"] = value
  
  	return nil
  }
docs: // CaptureStart implements the Tracer interface to initialize the tracing operation.