docstr: ...Test plot_hawkes_history rendering given a fitted Hawkes
  learner
code: def test_plot_hawkes_kernels(self):
      """...Test plot_hawkes_history rendering given a fitted Hawkes
      learner
      """
      decays = np.array([1.5, 3.5])
      hawkes_sumexp = HawkesSumExpKern(decays, max_iter=0)
      # We set some specific coeffs to be free from any future learner
      # modifications
      # With 0 iteration and coeffs as start point it should remain there
      coeffs = np.array(
          [0.99, 0.99, 0.55, 0.37, 0.39, 0.16, 0.63, 0.49, 0.49, 0.30]
      )
      hawkes_sumexp.fit(self.hawkes_simu.timestamps, start=coeffs)
  
      n_points = 10
      for support in [None, 4]:
          fig = plot_hawkes_kernels(
              hawkes_sumexp,
              hawkes=self.hawkes_simu,
              show=False,
              n_points=n_points,
              support=support,
          )
  
          if support is None:
              max_support = (
                  hawkes_sumexp.get_kernel_supports().max() * 1.2
              )
          else:
              max_support = support
  
          for i, j in itertools.product(range(self.n_nodes), repeat=2):
              index = i * self.n_nodes + j
              ax = fig.axes[index]
              ax_t_axis, ax_estimated_kernel = (
                  ax.lines[0].get_xydata().T
              )
              t_axis = np.linspace(0, max_support, n_points)
              np.testing.assert_array_equal(ax_t_axis, t_axis)
  
              estimated_kernel = hawkes_sumexp.get_kernel_values(
                  i, j, t_axis
              )
              np.testing.assert_array_equal(
                  ax_estimated_kernel, estimated_kernel
              )
  
              _, ax_true_kernel = ax.lines[1].get_xydata().T
              true_kernel = self.hawkes_simu.kernels[i, j].get_values(
                  t_axis
              )
              np.testing.assert_array_equal(ax_true_kernel, true_kernel)
  
file_path: tick/tick/plot/tests/plot_hawkes_test.py
imports: import unittest
  import numpy
  import itertools
  from tick.hawkes import HawkesSumExpKern
  from tick.plot import plot_hawkes_kernels
  from tick.hawkes import SimuHawkesSumExpKernels
label_desc: Use image node_id 2 for calling the Test obj's underlying member method code with example usage: obj.test_plot_hawkes_kernels() without return types