code: def test_mathieus():
      assert isinstance(mathieus(a, q, z), mathieus)
      assert mathieus(a, 0, z) == sin(sqrt(a) * z)
      assert conjugate(mathieus(a, q, z)) == mathieus(
          conjugate(a), conjugate(q), conjugate(z)
      )
      assert diff(mathieus(a, q, z), z) == mathieusprime(a, q, z)
  
file_path: sympy/sympy/functions/special/tests/test_mathieu.py
imports: from sympy.core.function import diff
  from sympy.functions.elementary.complexes import conjugate
  from sympy.functions.elementary.miscellaneous import sqrt
  from sympy.functions.elementary.trigonometric import cos, sin
  from sympy.functions.special.mathieu_functions import mathieuc, mathieucprime, mathieus, mathieusprime
  from sympy.abc import a, q, z
label_desc: Use image node_id 1 for calling a global function with example usage: test_mathieus() without return types