Get the column name in meta.data that works as identity
Source:R/scrna-macros.R
      GetIdentityColumn.RdGet the column name in meta.data that works as identity
Examples
obj <- SeuratObject::pbmc_small
GetIdentityColumn(obj)
#> [1] "RNA_snn_res.1"
SeuratObject::Idents(obj) <- "groups"
GetIdentityColumn(obj)
#> [1] "groups"