.
    If the input is a string, ignore all comments.
:type skip_whitespace: :obj:`bool`
:param skip_whitespace:
    Ignore whitespace at the top-level of the list.
    Whitespace is still preserved
    in the :attr:`~tinycss2.ast.Declaration.value` of declarations
    and the :attr:`~tinycss2.ast.AtRule.prelude`
    and :attr:`~tinycss2.ast.AtRule.content` of at-rules.
:returns:
    A list of
    :class:`~tinycss2.ast.Declaration`,
    :class:`~tinycss2.ast.AtRule`,
    :class:`~tinycss2.ast.QualifiedRule`,
    :class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false),
    :class:`~tinycss2.ast.WhitespaceToken`
    (if ``skip_whitespace`` is false),
    and :class:`~tinycss2.ast.ParseError` objects

r