def add_fields(row, attrs)
      fields = (@config.fields - @config.export_only_fields).map(&:to_s)
      fields.each do |name|
        row.has_key? name or next
        attrs[name] = row.field name
      end
    end
def add_fields(row, attrs)
      fields = (@config.fields - @config.export_only_fields).map(&:to_s)
      fields.each do |name|
        row.has_key? name or next
        attrs[name] = row.field name
      end
    end
Adds configured fields to attrs