class_docstr: Problem spec for parsing tokenized Icelandic text to constituency trees.
code: def num_shards(self):
      return 10
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import os
  from tensor2tensor.data_generators import generator_utils
  from tensor2tensor.data_generators import problem
  from tensor2tensor.data_generators import text_encoder
  from tensor2tensor.data_generators import text_problems
  from tensor2tensor.layers import modalities
  from tensor2tensor.utils import registry
label_desc: Use image node_id 5 for calling the ParsingIcelandic16k obj's underlying member method code with example usage: obj.num_shards() and returns: int