code: def test_polymatrix_rref():
      M = PolyMatrix([[1, 2], [3, 4]], x)
      assert M.rref() == (PolyMatrix.eye(2, x), (0, 1))
      raises(ValueError, lambda: PolyMatrix([1, 2], ring=ZZ[x]).rref())
      raises(ValueError, lambda: PolyMatrix([1, x], ring=QQ[x]).rref())
  
file_path: sympy/sympy/polys/tests/test_polymatrix.py
imports: from sympy.testing.pytest import raises
  from sympy.polys.polymatrix import PolyMatrix
  from sympy.polys import Poly
  from sympy.core.singleton import S
  from sympy.matrices.dense import Matrix
  from sympy.polys.domains.integerring import ZZ
  from sympy.polys.domains.rationalfield import QQ
  from sympy.abc import x, y
label_desc: Use image node_id 10 for calling a global function with example usage: test_polymatrix_rref() without return types