code: def test_from_summaries_null():
      d = DiracDelta([1, 2])
      d.from_summaries()
      assert_array_almost_equal(d.alphas, [1, 2])
      assert_array_almost_equal(d._log_alphas, numpy.log([1, 2]))
  
      d = DiracDelta([1, 2], inertia=0.5)
      d.from_summaries()
      assert_array_almost_equal(d.alphas, [1, 2])
      assert_array_almost_equal(d._log_alphas, numpy.log([1, 2]))
  
      d = DiracDelta([1, 2], inertia=0.5, frozen=True)
      d.from_summaries()
      assert_array_almost_equal(d.alphas, [1, 2])
      assert_array_almost_equal(d._log_alphas, numpy.log([1, 2]))
  
imports: import os
  import numpy
  import torch
  import pytest
  from pomegranate.distributions import DiracDelta
  from ._utils import _test_initialization_raises_one_parameter
  from ._utils import _test_initialization
  from ._utils import _test_predictions
  from ._utils import _test_efd_from_summaries
  from ._utils import _test_raises
  from nose.tools import assert_raises
  from numpy.testing import assert_array_almost_equal
label_desc: Use image node_id 22 for calling a global function with example usage: test_from_summaries_null() without return types