Fixed CSV writer to not write out samples during burn in period.
Fixed CSV writer to not write out samples during burn in period.

chunshen1987/DistributionSampling,chunshen1987/DistributionSampling,chunshen1987/DistributionSampling,chunshen1987/DistributionSampling,chunshen1987/DistributionSampling,chunshen1987/DistributionSampling