code: def _get_amplitudes(fig):
      # ignore the spatial_colors parasite axes
      regular_axes = [
          ax for ax in fig.axes if not isinstance(ax, HostAxes)
      ]
      amplitudes = [
          line.get_ydata()
          for ax in regular_axes
          for line in ax.get_lines()
      ]
      # this will exclude hlines, which are lists not arrays
      amplitudes = np.array(
          [line for line in amplitudes if isinstance(line, np.ndarray)]
      )
      return amplitudes
  
imports: from pathlib import Path
  import matplotlib.pyplot
  import numpy
  import pytest
  from matplotlib import gridspec
  from matplotlib.collections import PolyCollection
  from matplotlib.colors import same_color
  from mpl_toolkits.axes_grid1.parasite_axes import HostAxes
  from numpy.testing import assert_allclose
  import mne
  from mne import Epochs, compute_covariance, compute_proj_evoked, make_fixed_length_events, read_cov, read_events
  from mne._fiff.constants import FIFF
  from mne.datasets import testing
  from mne.io import read_raw_fif
  from mne.stats.parametric import _parametric_ci
  from mne.utils import catch_logging
  from mne.viz import plot_compare_evokeds, plot_evoked_white
  from mne.viz.utils import _fake_click, _get_cmap
label_desc: Use image node_id 6 for calling a global function with example usage: _get_amplitudes(fig) and returns: amplitudes