def columns=(array)
      @_header_adjustment = 1
      @columns = array
      @columns.each_with_index { |c,i| 
        @cw[i] ||= c.to_s.length
        @calign[i] ||= :left
      }
      # maintains index in current pointer and gives next or prev
      @column_pointer = Circular.new @columns.size()-1
    end
def columns=(array)
      @_header_adjustment = 1
      @columns = array
      @columns.each_with_index { |c,i| 
        @cw[i] ||= c.to_s.length
        @calign[i] ||= :left
      }
      # maintains index in current pointer and gives next or prev
      @column_pointer = Circular.new @columns.size()-1
    end
set column names
 @param [Array] column names or headings