sage: A = QuaternionMatrixAlgebra(ZZ.random_element(10))
sage: x = A.random_element()
sage: x*A.one() == x and A.one()*x == x
sage: A = QuaternionMatrixAlgebra(ZZ.random_element(10))
sage: x = A.random_element()
sage: x*A.one() == x and A.one()*x == x