class_docstr: Test that the functions return an axis date type.
class_docstr_tok: ["Test","that","the","functions","return","an","axis","date","type","."]
docstr: Test that invalid axes are not plotted on.
docstr_tok: ["Test","that","invalid","axes","are","not","plotted","on","."]
code: def test_correct_return_type(
      self, func, coeffs, n_inputs, ax, show_freqs
  ):
      """Test that invalid axes are not plotted on."""
      if show_freqs is None:
          res = func(coeffs, n_inputs, ax)
      else:
          res = func(coeffs, n_inputs, ax, show_freqs=show_freqs)
  
      assert isinstance(res, type(ax))
  
file_path: pennylane/tests/fourier/test_visualize.py
imports: import pytest
  from pennylane import numpy
  from pennylane.fourier.visualize import _validate_coefficients
  from pennylane.fourier.visualize import violin, bar, box, panel, radial_box
label_desc: Use image node_id 1 for calling the TestReturnType obj's underlying member method code with example usage: obj.test_correct_return_type(func, coeffs, n_inputs, ax, show_freqs) without return types