ds.where inserts _id data when passing array as value to columns option

[allthesignals]

var cut = ds.where({ columns: config.data
                     , rows: function(row) { 
                          return row[config.where.column] == config.where.value } 
                    })

I'm just trying to understand this better, and maybe this isn't the proper use case, but when using an array from an object in the columns property, I notice _id data is pushed into the config.data array. Is this intended?