# File lib/faster_csv.rb, line 632
    def delete_if(&block)
      if @mode == :row or @mode == :col_or_row  # by index
        @table.delete_if(&block)
      else                                      # by header
        to_delete = Array.new
        headers.each_with_index do |header, i|
          to_delete << header if block[[header, self[header]]]
        end
        to_delete.map { |header| delete(header) }
      end
      
      self  # for chaining
    end