code: def get(cls, id):
          
  
          # cached?
          if CACHE:
              if id in _cache['Prefix']:
                  log.debug('cache hit for prefix %d' % id)
                  return _cache['Prefix'][id]
              log.debug('cache miss for prefix %d' % id)
  
          try:
              prefix = Prefix.list({'id': id})[0]
          except IndexError:
              raise NipapNonExistentError('no prefix with ID ' + str(id) + ' found')
  
          _cache['Prefix'][id] = prefix
          return prefix
docs: Get the prefix with id 'id'.