Create an empty cohort definition set
Source:R/CohortDefinitionSet.R
      createEmptyCohortDefinitionSet.RdThis function creates an empty cohort set data.frame for use
with generateCohortSet.
R/CohortDefinitionSet.R
      createEmptyCohortDefinitionSet.RdThis function creates an empty cohort set data.frame for use
with generateCohortSet.