Validate and split input data
.parse_inputs(data, label = NULL, unlabeled_data = NULL, na_action = "na.fail")A list with components data_l and data_u (data.frames)
data.frame or coercible object
optional column flagging labeled vs. unlabeled rows
optional data.frame of unlabeled observations
how to handle missing data: "na.fail" or "na.omit"