docstr: Tests a few known exponential kernel results.
docstr_tok: ["Tests","a","few","known","exponential","kernel","results","."]
code: def test_exponential_kernel(self, distance, kernel_width, expected):
      """Tests a few known exponential kernel results."""
      result = lime.exponential_kernel(distance, kernel_width)
      np.testing.assert_almost_equal(expected, result)
  
imports: import collections
  import functools
  from absl.testing import absltest
  from absl.testing import parameterized
  from lime import lime_text
  from lit_nlp.components.citrus import lime
  from lit_nlp.components.citrus import utils
  import numpy
  from scipy import special
  from scipy import stats
label_desc: Use image node_id 5 for calling the LimeTest obj's underlying member method code with example usage: obj.test_exponential_kernel(distance, kernel_width, expected) without return types