How to use the pysubs2.substation.parse_tags function in pysubs2

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

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

def test_no_tags():
    text = "Hello, world!"
    assert parse_tags(text) == [(text, SSAStyle())]

def prepare_text(text, style):
            body = []
            for fragment, sty in parse_tags(text, style, subs.styles):
                fragment = fragment.replace(r"\h", " ")
                fragment = fragment.replace(r"\n", "\n")
                fragment = fragment.replace(r"\N", "\n")
                if sty.italic: fragment = "<i>%s</i>" % fragment
                if sty.underline: fragment = "<u>%s</u>" % fragment
                if sty.strikeout: fragment = "<s>%s</s>" % fragment
                body.append(fragment)

            return re.sub("\n+", "\n", "".join(body).strip())

def is_entirely_italic(line):
            style = subs.styles.get(line.style, SSAStyle.DEFAULT_STYLE)
            for fragment, sty in parse_tags(line.text, style, subs.styles):
                fragment = fragment.replace(r"\h", " ")
                fragment = fragment.replace(r"\n", "\n")
                fragment = fragment.replace(r"\N", "\n")
                if not sty.italic and fragment and not fragment.isspace():
                    return False
            return True

def prepare_text(text, style):
            body = []
            for fragment, sty in parse_tags(text, style, subs.styles):
                fragment = fragment.replace(r"\h", " ")
                fragment = fragment.replace(r"\n", "\n")
                fragment = fragment.replace(r"\N", "\n")
                if sty.italic: fragment = "<i>%s</i>" % fragment
                if sty.underline: fragment = "<u>%s</u>" % fragment
                if sty.strikeout: fragment = "<s>%s</s>" % fragment
                body.append(fragment)

            return re.sub("\n+", "\n", "".join(body).strip())