code: def adjust_attribute_sequence(*fields):
  	
  	
  	amount = None
  	
  	if fields and isinstance(fields[0], int):
  		amount, fields = fields[0], fields[1:]
  	
  	def adjust_inner(cls):
  		for field in fields:
  			if field not in cls.__dict__:
  				# TODO: Copy the field definition.
  				raise TypeError("Can only override sequence on non-inherited attributes.")
  			
  			# Adjust the sequence to re-order the field.
  			if amount is None:
  				cls.__dict__[field].__sequence__ = ElementMeta.sequence
  			else:
  				cls.__dict__[field].__sequence__ += amount  # Add the given amount.
  		
  		# Update the attribute collection.
  		cls.__attributes__ = OrderedDict(
  					(k, v) for k, v in \
  					sorted(cls.__attributes__.items(),
  						key=lambda i: i[1].__sequence__)
  				)
  		
  		return cls
  	
  	return adjust_inner
docs: Move marrow.schema fields around to control positional instantiation order.