def write_filters(*filters) #:nodoc:
      if filters.size == 1 && filters[0] == 'blanks'
        # Special case for blank cells only.
        @writer.empty_tag('filters', [ ['blank', 1] ])
      else
        # General case.
        @writer.tag_elements('filters') do
          filters.each { |filter| write_filter(filter) }
        end
      end
    end
def write_filters(*filters) #:nodoc:
      if filters.size == 1 && filters[0] == 'blanks'
        # Special case for blank cells only.
        @writer.empty_tag('filters', [ ['blank', 1] ])
      else
        # General case.
        @writer.tag_elements('filters') do
          filters.each { |filter| write_filter(filter) }
        end
      end
    end
Write the <filters> element.