code: def test_initialize(X):
      d = [Exponential(), Exponential()]
      model = GeneralMixtureModel(d, init="first-k")
  
      assert model.d is None
      assert model.k == 2
      assert model._initialized == False
      assert_raises(AttributeError, getattr, model, "_w_sum")
      assert_raises(AttributeError, getattr, model, "_log_priors")
  
      model._initialize(X)
      assert model._initialized == True
      assert model.priors.shape[0] == 2
      assert model.d == 3
      assert model.k == 2
      assert_array_almost_equal(model.priors, [0.363636, 0.636364])
      assert_array_almost_equal(model._w_sum, [0.0, 0.0])
  
imports: import os
  import numpy
  import torch
  import pytest
  from pomegranate.gmm import GeneralMixtureModel
  from pomegranate.distributions import Exponential
  from .distributions._utils import _test_initialization_raises_one_parameter
  from .distributions._utils import _test_initialization
  from .distributions._utils import _test_predictions
  from .distributions._utils import _test_efd_from_summaries
  from .distributions._utils import _test_raises
  from nose.tools import assert_raises
  from numpy.testing import assert_array_almost_equal
label_desc: Use image node_id 8 for calling a global function with example usage: test_initialize(X) without return types