tracing/tracing.go
func (p StartParams) WithStreamFormat(streamFormat StreamFormat) *StartParams {
	p.StreamFormat = streamFormat
	return &p
}
func (p StartParams) WithStreamFormat(streamFormat StreamFormat) *StartParams {
	p.StreamFormat = streamFormat
	return &p
}
// WithStreamFormat trace data format to use. This only applies when using
// ReturnAsStream transfer mode (defaults to json).