code: def add(self, i: int):
      return Span(start=self.start + i, end=self.end + i)
  
imports: import numpy
  from dataclasses import dataclass
  from typing import List, NamedTuple
  from jiant.tasks.core import FeaturizationSpec
  from jiant.tasks.utils import truncate_sequences, pad_to_max_seq_length
  from jiant.utils.python.datastructures import BiMap
label_desc: Use image node_id 1 for calling the Span obj's underlying member method code with example usage: obj.add(i) and returns: Span