code: def test_mdft():
      with warns_deprecated_sympy():
          assert mdft(1) == Matrix([[1]])
      with warns_deprecated_sympy():
          assert mdft(2) == 1 / sqrt(2) * Matrix([[1, 1], [1, -1]])
      with warns_deprecated_sympy():
          assert mdft(4) == Matrix(
              [
                  [S.Half, S.Half, S.Half, S.Half],
                  [S.Half, -I / 2, Rational(-1, 2), I / 2],
                  [S.Half, Rational(-1, 2), S.Half, Rational(-1, 2)],
                  [S.Half, I / 2, Rational(-1, 2), -I / 2],
              ]
          )
  
file_path: sympy/sympy/physics/tests/test_physics_matrices.py
imports: from sympy.physics.matrices import msigma, mgamma, minkowski_tensor, pat_matrix, mdft
  from sympy.core.numbers import I, Rational
  from sympy.core.singleton import S
  from sympy.functions.elementary.miscellaneous import sqrt
  from sympy.matrices.dense import Matrix, eye, zeros
  from sympy.testing.pytest import warns_deprecated_sympy
label_desc: Use image node_id 4 for calling a global function with example usage: test_mdft() without return types