def self.write_one(object, writer, singular = nil)
singular ||= 'backup'
writer.write_start(singular)
href = object.href
writer.write_attribute('href', href) unless href.nil?
writer.write_attribute('id', object.id) unless object.id.nil?
Writer.write_string(writer, 'comment', object.comment) unless object.comment.nil?
Writer.write_date(writer, 'creation_date', object.creation_date) unless object.creation_date.nil?
Writer.write_string(writer, 'description', object.description) unless object.description.nil?
Writer.write_string(writer, 'from_checkpoint_id', object.from_checkpoint_id) unless object.from_checkpoint_id.nil?
Writer.write_string(writer, 'name', object.name) unless object.name.nil?
Writer.write_string(writer, 'phase', object.phase) unless object.phase.nil?
Writer.write_string(writer, 'to_checkpoint_id', object.to_checkpoint_id) unless object.to_checkpoint_id.nil?
DiskWriter.write_many(object.disks, writer, 'disk', 'disks') unless object.disks.nil?
VmWriter.write_one(object.vm, writer, 'vm') unless object.vm.nil?
writer.write_end
end