code: def test_DomainScalar_isOne():
      A = DomainScalar(ZZ(1), ZZ)
      assert A.is_one() == True
      B = DomainScalar(ZZ(0), ZZ)
      assert B.is_one() == False
  
imports: from sympy.testing.pytest import raises
  from sympy.core.symbol import S
  from sympy.polys import ZZ, QQ
  from sympy.polys.matrices.domainscalar import DomainScalar
  from sympy.polys.matrices.domainmatrix import DomainMatrix
label_desc: Use image node_id 20 for calling a global function with example usage: test_DomainScalar_isOne() without return types