def test_calculator_01():
    assert (solver.calculator('=((1+3)*2)/(6-4)') == 4)
    assert (solver.calculator('((1+3)*2)/(6-4)') == '((1+3)*2)/(6-4)')
    assert (solver.calculator('=hola') == 'hola')
def test_calculator_01():
    assert (solver.calculator('=((1+3)*2)/(6-4)') == 4)
    assert (solver.calculator('((1+3)*2)/(6-4)') == '((1+3)*2)/(6-4)')
    assert (solver.calculator('=hola') == 'hola')