Column names; last is response for supervised models
_domains
java.lang.String[][] _domains
Categorical/factor/enum mappings, per column. Null for non-enum cols.
Columns match the post-init cleanup columns. The last column holds the
response col enums for SupervisedModels.
Package hex.genmodel.easy
Class hex.genmodel.easy.RowData extends java.util.HashMap<java.lang.String,java.lang.Object> implements Serializable