How to use the sure.this function in sure

def opposite():
        assert this("foo").should.be.callable

def test_lower_than():
    ("this(X).should.be.lower_than(Y)")

    assert this(4).should.be.lower_than(5)
    assert this(2).should_not.be.lower_than(1)

    def opposite():
        assert this(5).should.be.lower_than(4)

    def opposite_not():
        assert this(1).should_not.be.lower_than(2)

    expect(opposite).when.called.to.throw(AssertionError)
    expect(opposite).when.called.to.throw(
        "expected `5` to be lower than `4`")

    expect(opposite_not).when.called.to.throw(AssertionError)
    expect(opposite_not).when.called.to.throw(
        "expected `1` to not be lower than `2`")

def test_false_be_falsy():
    ("this(False).should.be.false")

    assert this(False).should.be.falsy
    assert this(True).should_not.be.falsy

    def opposite():
        assert this(True).should.be.falsy

    def opposite_not():
        assert this(False).should_not.be.falsy

    expect(opposite).when.called.to.throw(AssertionError)
    expect(opposite).when.called.to.throw("expected `True` to be falsy")

    expect(opposite_not).when.called.to.throw(AssertionError)
    expect(opposite_not).when.called.to.throw("expected `False` to be truthy")

def opposite_not():
        assert this("some string").should_not.contain(r"string")

def opposite():
        assert this(1).should_not.be.an(int)

def opposite_not():
        assert this({}).should_not.be.empty

def test_false_be_falsy():
    ("this(False).should.be.false")

    assert this(False).should.be.falsy
    assert this(True).should_not.be.falsy

    def opposite():
        assert this(True).should.be.falsy

    def opposite_not():
        assert this(False).should_not.be.falsy

    expect(opposite).when.called.to.throw(AssertionError)
    expect(opposite).when.called.to.throw("expected `True` to be falsy")

    expect(opposite_not).when.called.to.throw(AssertionError)
    expect(opposite_not).when.called.to.throw("expected `False` to be truthy")

def opposite():
        assert this(5).should.be.lower_than(4)

def test_2_within_0a2():
    ("this(1).should.be.within(0, 2)")

    assert this(1).should.be.within(0, 2)
    assert this(4).should_not.be.within(0, 2)

    def opposite():
        assert this(1).should.be.within(2, 4)

    def opposite_not():
        assert this(1).should_not.be.within(0, 2)

    expect(opposite).when.called.to.throw(AssertionError)
    expect(opposite).when.called.to.throw("expected 1 to be within 2 and 4")

    expect(opposite_not).when.called.to.throw(AssertionError)
    expect(opposite_not).when.called.to.throw("expected 1 to NOT be within 0 and 2")

def test_greater_than():
    ("this(X).should.be.greater_than(Y)")

    assert this(5).should.be.greater_than(4)
    assert this(1).should_not.be.greater_than(2)

    def opposite():
        assert this(4).should.be.greater_than(5)

    def opposite_not():
        assert this(2).should_not.be.greater_than(1)

    expect(opposite).when.called.to.throw(AssertionError)
    expect(opposite).when.called.to.throw(
        "expected `4` to be greater than `5`")

    expect(opposite_not).when.called.to.throw(AssertionError)
    expect(opposite_not).when.called.to.throw(
        "expected `2` to not be greater than `1`")