class Playbook::PbAdvancedTable::TableBody

def flatten_columns(columns)
  columns.flat_map do |col|
    if col[:columns]
      flatten_columns(col[:columns])
    elsif col[:accessor].present?
      if has_grouped_headers?
        col.merge(is_last_in_group: last_in_group?(columns, col))
      else
        col
      end
    end
  end.compact
end