code: def test_depth_silhouette_eq(default_theme):
      my_theme = pv.plotting.themes.Theme()
      my_theme.silhouette.opacity = 0.11111
      assert my_theme.silhouette != default_theme.silhouette
      assert my_theme.silhouette != 1
  
imports: import os
  import pytest
  import vtk
  import pyvista
  from pyvista import colors
  from pyvista.examples.downloads import download_file
  from pyvista.plotting.themes import DarkTheme, Theme, _set_plot_theme_from_env
  from pyvista.plotting.utilities.gl_checks import uses_egl
label_desc: Use image node_id 5 for calling a global function with example usage: test_depth_silhouette_eq(default_theme) without return types