code: def test_expon_fit():
      """gh-6167"""
      data = [0, 0, 0, 0, 2, 2, 2, 2]
      phat = stats.expon.fit(data, floc=0)
      assert_allclose(phat, [0, 1.0], atol=1e-3)
  
file_path: catboost/contrib/python/scipy/py3/scipy/stats/tests/test_fit.py
imports: import os
  import numpy
  from numpy.testing import assert_allclose
  import pytest
  from scipy import stats
  from .test_continuous_basic import distcont
label_desc: Use image node_id 5 for calling a global function with example usage: test_expon_fit() without return types