def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def _ui_font_style(layout, font_style):

        split = layout.split()

        col = split.column()
        col.label(text="Kerning Style:")
        col.row().prop(font_style, "font_kerning_style", expand=True)
        col.prop(font_style, "points")

        col = split.column()
        col.label(text="Shadow Offset:")
        col.prop(font_style, "shadow_offset_x", text="X")
        col.prop(font_style, "shadow_offset_y", text="Y")

        col = split.column()
        col.prop(font_style, "shadow")
        col.prop(font_style, "shadow_alpha")
        col.prop(font_style, "shadow_value")

        layout.separator()