code: def test_value_step_rectangle(form, lineshape):
      """Test values at mu1/mu2 for step- and rectangle-functions."""
      func = getattr(lmfit.lineshapes, lineshape)
      # at position mu1 we should be at A/2
      assert_almost_equal(func(0), 0.5)
      # for a rectangular shape we have the same at mu2
      if lineshape == "rectangle":
          assert_almost_equal(func(1), 0.5)
  
file_path: lmfit-py/tests/test_lineshapes.py
imports: import inspect
  import numpy
  from numpy.testing import assert_almost_equal
  import pytest
  import lmfit
  from lmfit.lineshapes import not_zero, tiny
label_desc: Use image node_id 5 for calling a global function with example usage: test_value_step_rectangle(form, lineshape) without return types