How to use the pysubs2.SSAStyle function in pysubs2

def test_r_tag():
    text = "{\\i1}Hello, {\\r}world!"
    assert parse_tags(text) == [("", SSAStyle()),
                                ("Hello, ", SSAStyle(italic=True)),
                                ("world!", SSAStyle())]

def test_r_tag():
    text = "{\\i1}Hello, {\\r}world!"
    assert parse_tags(text) == [("", SSAStyle()),
                                ("Hello, ", SSAStyle(italic=True)),
                                ("world!", SSAStyle())]

def test_rename_style():
    subs = SSAFile()
    red = SSAStyle()
    green = SSAStyle()

    def prepare():
        subs.events = [SSAEvent(style="red"), SSAEvent(style="unrelated")]
        subs.styles = dict(red=red, green=green)

    prepare()
    subs.rename_style("red", "blue")
    assert "red" not in subs.styles
    assert subs.styles["blue"] is red
    assert subs[0].style == "blue"
    assert subs[1].style == "unrelated"

    prepare()
    with assert_raises(ValueError):
        # cannot delete style via move
        subs.rename_style("red", "green")

def test_import_styles():
    red1 = SSAStyle()
    red2 = SSAStyle()
    green = SSAStyle()
    subs1 = SSAFile()
    subs2 = SSAFile()

    def prepare():
        subs1.styles = {}
        subs2.styles = {}
        subs1.styles["green"] = green
        subs1.styles["red"] = red1
        subs2.styles["red"] = red2

    prepare()
    subs2.import_styles(subs1)
    assert subs2.styles["green"] is green
    assert subs2.styles["red"] is red1

def test_i_tag():
    text = "Hello, {\\i1}world{\\i0}!"
    assert parse_tags(text) == [("Hello, ", SSAStyle()),
                                ("world", SSAStyle(italic=True)),
                                ("!", SSAStyle())]

def test_import_styles():
    red1 = SSAStyle()
    red2 = SSAStyle()
    green = SSAStyle()
    subs1 = SSAFile()
    subs2 = SSAFile()

    def prepare():
        subs1.styles = {}
        subs2.styles = {}
        subs1.styles["green"] = green
        subs1.styles["red"] = red1
        subs2.styles["red"] = red2

    prepare()
    subs2.import_styles(subs1)
    assert subs2.styles["green"] is green
    assert subs2.styles["red"] is red1

def test_r_named_tag():
    styles = {"other style": SSAStyle(bold=True)}
    text = "Hello, {\\rother style\\i1}world!"
    
    assert parse_tags(text, styles=styles) == \
        [("Hello, ", SSAStyle()),
         ("world!", SSAStyle(italic=True, bold=True))]

def build_ref():
    subs = SSAFile()
    subs.info["My Custom Info"] = "Some: Test, String."
    subs.styles["left"] = SSAStyle(alignment=7, bold=True)
    subs.styles["topleft"] = SSAStyle(alignment=4)
    subs.append(SSAEvent(start=0, end=make_time(m=1), text="An, example, subtitle."))
    subs.append(SSAEvent(start=0, end=make_time(m=1), type="Comment", text="You can't see this one."))
    subs.append(SSAEvent(start=make_time(m=1), end=make_time(m=2), text="Subtitle number\\Ntwo."))
    return subs

def test_import_styles():
    red1 = SSAStyle()
    red2 = SSAStyle()
    green = SSAStyle()
    subs1 = SSAFile()
    subs2 = SSAFile()

    def prepare():
        subs1.styles = {}
        subs2.styles = {}
        subs1.styles["green"] = green
        subs1.styles["red"] = red1
        subs2.styles["red"] = red2

    prepare()
    subs2.import_styles(subs1)
    assert subs2.styles["green"] is green
    assert subs2.styles["red"] is red1

    prepare()