code: def model_constructors(vk, model):
      
      model['constructors'] = []
      structs = [x for x in vk['registry']['types']['type']
                 if x.get('@category') in {'struct', 'union'}]
  
      def parse_len(member):
          mlen = member.get('@len')
          if not mlen:
              return None
  
          if ',' in mlen:
              mlen = mlen.split(',')[0]
  
          if 'latex' in mlen or 'null-terminated' in mlen:
              return None
  
          return mlen
  
      for struct in structs:
          if 'member' not in struct:
              continue
  
          model['constructors'].append({
              'name': struct['@name'],
              'members': [{
                  'name': x['name'],
                  'type': x['type'],
                  'default': x.get('@values'),
                  'len': parse_len(x)
              } for x in struct['member']]
          })
docs: Fill the model with constructors
  
      model['constructors'] = [{'name': 'x', 'members': [{'name': 'y'}].}]