code: def test_as_tensor_converts_span_field_correctly(self):
      span_field = SpanField(2, 3, self.text)
      tensor = (
          span_field.as_tensor(span_field.get_padding_lengths())
          .detach()
          .cpu()
          .numpy()
      )
      numpy.testing.assert_array_equal(tensor, numpy.array([2, 3]))
  
file_path: allennlp/tests/data/fields/span_field_test.py
imports: import numpy
  import pytest
  from allennlp.common.testing import AllenNlpTestCase
  from allennlp.data import Token
  from allennlp.data.fields import TextField, SpanField
  from allennlp.data.token_indexers import SingleIdTokenIndexer
label_desc: Use image node_id 2 for calling the TestSpanField obj's underlying member method code with example usage: obj.test_as_tensor_converts_span_field_correctly() without return types