code: def test_DDM_neg():
      A = DDM([[ZZ(1)], [ZZ(2)]], (2, 1), ZZ)
      An = DDM([[ZZ(-1)], [ZZ(-2)]], (2, 1), ZZ)
      assert -A == A.neg() == An
      assert -An == An.neg() == A
  
imports: from sympy.testing.pytest import raises
  from sympy.external.gmpy import GROUND_TYPES
  from sympy.polys import ZZ, QQ
  from sympy.polys.matrices.ddm import DDM
  from sympy.polys.matrices.exceptions import DMShapeError, DMNonInvertibleMatrixError, DMDomainError, DMBadInputError
label_desc: Use image node_id 13 for calling a global function with example usage: test_DDM_neg() without return types