def each_capitalized
      block_given? or return enum_for(__method__)
      @header.each do |k,v|
        yield capitalize(k), v.join(', ')
      end
    end
def each_capitalized
      block_given? or return enum_for(__method__)
      @header.each do |k,v|
        yield capitalize(k), v.join(', ')
      end
    end
As for #each_header, except the keys are provided in capitalized form.