I have a model DrawingRequest

class DrawingRequest(models.Model):

[...]

drawings = fields.One2many('drawing.document', 'drawing_request_id', string='Drawings', tracking=True)

and a model drawing document

class DrawingDocument(models.Model):

_name = 'drawing.document'

_order = 'sequence,id'



sequence = fields.Integer('Sequence')

document = fields.Binary(string='Document', attachment=True)

filename = fields.Char('Filename')

drawing_request_id = fields.Many2one(

'drawing.request', "Drawing request", tracking=True)

I  would  like  to  refer  to  the  'first'  (they  are  sequenced)  DrawingDocument  from  my  DrawingRequest  

What is the easiest way to refer to this first DrawingDocument from a tree list of DrawingRequests ?