class_docstr: Used to verify if users can create their own backends.
  This backend is meant to pass all tests.
class_docstr_tok: ["Used","to","verify","if","users","can","create","their","own","backends",".","This","backend","is","meant","to","pass","all","tests","."]
code: def show(self):
      pass
  
imports: import os
  from tempfile import TemporaryDirectory
  import pytest
  from sympy.concrete.summations import Sum
  from sympy.core.numbers import I, oo, pi
  from sympy.core.relational import Ne
  from sympy.core.symbol import Symbol, symbols
  from sympy.functions.elementary.exponential import LambertW, exp, exp_polar, log
  from sympy.functions.elementary.miscellaneous import real_root, sqrt
  from sympy.functions.elementary.piecewise import Piecewise
  from sympy.functions.elementary.trigonometric import cos, sin
  from sympy.functions.elementary.miscellaneous import Min
  from sympy.functions.special.hyper import meijerg
  from sympy.integrals.integrals import Integral
  from sympy.logic.boolalg import And
  from sympy.core.singleton import S
  from sympy.core.sympify import sympify
  from sympy.external import import_module
  from sympy.plotting.plot import Plot, plot, plot_parametric, plot3d_parametric_line, plot3d, plot3d_parametric_surface
  from sympy.plotting.plot import unset_show, plot_contour, PlotGrid, MatplotlibBackend, TextBackend
  from sympy.plotting.series import LineOver1DRangeSeries, Parametric2DLineSeries, Parametric3DLineSeries, ParametricSurfaceSeries, SurfaceOver2DRangeSeries
  from sympy.testing.pytest import skip, warns, raises, warns_deprecated_sympy
  from sympy.utilities import lambdify
  from sympy.utilities.exceptions import ignore_warnings
label_desc: Use image node_id 2 for calling the DummyBackendOk obj's underlying member method code with example usage: obj.show() without return types