code: def test_heaviside():
      assert Heaviside(-5) == 0
      assert Heaviside(1) == 1
      assert Heaviside(0) == S.Half
  
      assert Heaviside(0, x) == x
      assert unchanged(Heaviside, x, nan)
      assert Heaviside(0, nan) == nan
  
      h0 = Heaviside(x, 0)
      h12 = Heaviside(x, S.Half)
      h1 = Heaviside(x, 1)
  
      assert h0.args == h0.pargs == (x, 0)
      assert h1.args == h1.pargs == (x, 1)
      assert h12.args == (x, S.Half)
      assert h12.pargs == (x,)  # default 1/2 suppressed
  
      assert adjoint(Heaviside(x)) == Heaviside(x)
      assert adjoint(Heaviside(x - y)) == Heaviside(x - y)
      assert conjugate(Heaviside(x)) == Heaviside(x)
      assert conjugate(Heaviside(x - y)) == Heaviside(x - y)
      assert transpose(Heaviside(x)) == Heaviside(x)
      assert transpose(Heaviside(x - y)) == Heaviside(x - y)
  
      assert Heaviside(x).diff(x) == DiracDelta(x)
      assert Heaviside(x + I).is_Function is True
      assert Heaviside(I * x).is_Function is True
  
      raises(ArgumentIndexError, lambda: Heaviside(x).fdiff(2))
      raises(ValueError, lambda: Heaviside(I))
      raises(ValueError, lambda: Heaviside(2 + 3 * I))
  
file_path: sympy/sympy/functions/special/tests/test_delta_functions.py
imports: from sympy.core.numbers import I, nan, oo, pi
  from sympy.core.relational import Eq, Ne
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol, symbols
  from sympy.functions.elementary.complexes import adjoint, conjugate, sign, transpose
  from sympy.functions.elementary.miscellaneous import sqrt
  from sympy.functions.elementary.piecewise import Piecewise
  from sympy.functions.special.delta_functions import DiracDelta, Heaviside
  from sympy.functions.special.singularity_functions import SingularityFunction
  from sympy.simplify.simplify import signsimp
  from sympy.testing.pytest import raises
  from sympy.core.expr import unchanged
  from sympy.core.function import ArgumentIndexError
label_desc: Use image node_id 2 for calling a global function with example usage: test_heaviside() without return types