1. Steven Winter is Ph.D. Student, Department of Statistical Science, Duke University, Durham, North Carolina 27710, USA
2. Trevor Campbell is Associate Professor, Department of Statistics, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
3. Lizhen Lin is Robert and Sara Lumpkins Associate Professor, Department of Applied and Computational Mathematics and Statistics, University of Notre Dame, Notre Dame, Indiana 46556, USA
4. Sanvesh Srivastava is Associate Professor, Department of Statistics and Actuarial Science, University of Iowa, Iowa City, Iowa 52242, USA
5. David B. Dunson is Arts and Sciences Distinguished Professor, Departments of Statistical Science and Mathematics, Duke University, Durham, North Carolina 27710, USA