sage: entries = QuaternionAlgebra(QQ,-1,-1)
sage: M = MatrixAlgebra(3, entries, QQ)
sage: M.random_element().matrix_space() == M
sage: entries = QuaternionAlgebra(QQ,-1,-1)
sage: M = MatrixAlgebra(3, entries, QQ)
sage: M.random_element().matrix_space() == M