How to use the libcst._nodes.base.CSTNode function in libcst

name=visit_required(self, "name", self.name, visitor),
            whitespace_after_as=visit_required(
                self, "whitespace_after_as", self.whitespace_after_as, visitor
            ),
        )

    def _codegen_impl(self, state: CodegenState) -> None:
        self.whitespace_before_as._codegen(state)
        state.add_token("as")
        self.whitespace_after_as._codegen(state)
        self.name._codegen(state)


@add_slots
@dataclass(frozen=True)
class ExceptHandler(CSTNode):
    """
    An ``except`` clause that appears optionally after a :class:`Try` statement.
    """

    #: The body of the except.
    body: BaseSuite

    #: The type of exception this catches. Can be a tuple in some cases,
    #: or ``None`` if the code is catching all exceptions.
    type: Optional[BaseExpression] = None

    #: The optional name that a caught exception is assigned to.
    name: Optional[AsName] = None

    #: Sequence of empty lines appearing before this compound statement line.
    leading_lines: Sequence[EmptyLine] = ()

state.add_token("yield")
            whitespace_after_yield = self.whitespace_after_yield
            if isinstance(whitespace_after_yield, BaseParenthesizableWhitespace):
                whitespace_after_yield._codegen(state)
            else:
                # Only need a space after yield if there is a value to yield.
                if self.value is not None:
                    state.add_token(" ")
            value = self.value
            if isinstance(value, From):
                value._codegen(state, default_space="")
            elif value is not None:
                value._codegen(state)


class _BaseElementImpl(CSTNode, ABC):
    """
    An internal base class for :class:`Element` and :class:`DictElement`.
    """

    value: BaseExpression
    comma: Union[Comma, MaybeSentinel] = MaybeSentinel.DEFAULT

    def _codegen_comma(
        self,
        state: CodegenState,
        default_comma: bool = False,
        default_comma_whitespace: bool = False,  # False for a single-item collection
    ) -> None:
        """
        Called by `_codegen_impl` in subclasses to generate the comma.
        """

"""

    #: The comment itself. Valid values start with the pound (``#``) character followed
    #: by zero or more non-newline characters. Comments cannot include newlines.
    value: str

    def _validate(self) -> None:
        if COMMENT_RE.fullmatch(self.value) is None:
            raise CSTValidationError(
                f"Got non-comment value for comment node: {repr(self.value)}"
            )


@add_slots
@dataclass(frozen=True)
class TrailingWhitespace(CSTNode):
    """
    The whitespace at the end of a line after a statement. If a line contains only
    whitespace, :class:`EmptyLine` should be used instead.
    """

    #: Any simple whitespace before any comment or newline.
    whitespace: SimpleWhitespace = SimpleWhitespace.field("")

    #: An optional comment appearing after any simple whitespace.
    comment: Optional[Comment] = None

    #: The newline character that terminates this trailing whitespace.
    newline: Newline = Newline.field()

    def _visit_and_replace_children(self, visitor: CSTVisitorT) -> "TrailingWhitespace":
        return TrailingWhitespace(

for i, arg in enumerate(args):
                arg._codegen(state, default_comma=(i != last_arg))
            rpar = self.rpar
            if isinstance(rpar, MaybeSentinel):
                if self.bases or self.keywords:
                    state.add_token(")")
            elif isinstance(rpar, RightParen):
                rpar._codegen(state)
            self.whitespace_before_colon._codegen(state)
            state.add_token(":")
            self.body._codegen(state)


@add_slots
@dataclass(frozen=True)
class WithItem(CSTNode):
    """
    A single context manager in a :class:`With` block, with an optional variable name.
    """

    #: Expression that evaluates to a context manager.
    item: BaseExpression

    #: Variable to assign the context manager to, if it is needed in the
    #: :class:`With` body.
    asname: Optional[AsName] = None

    #: This is forbidden for the last :class:`WithItem` in a :class:`With`, but all
    #: other items inside a with block must contain a comma to separate them.
    comma: Union[Comma, MaybeSentinel] = MaybeSentinel.DEFAULT

    def _visit_and_replace_children(self, visitor: CSTVisitorT) -> "WithItem":

and not isinstance(self.params.star_arg, Param)
                    and len(self.params.kwonly_params) == 0
                    and self.params.star_kwarg is None
                ):
                    # We have one or more params, provide a space
                    state.add_token(" ")
            elif isinstance(whitespace_after_lambda, BaseParenthesizableWhitespace):
                whitespace_after_lambda._codegen(state)
            self.params._codegen(state)
            self.colon._codegen(state)
            self.body._codegen(state)


@add_slots
@dataclass(frozen=True)
class Arg(CSTNode):
    """
    A single argument to a :class:`Call`.

    This supports named keyword arguments in the form of ``keyword=value`` and variable
    argument expansion using ``*args`` or ``**kwargs`` syntax.
    """

    #: The argument expression itself, not including a preceding keyword, or any of
    #: the surrounding the value, like a comma or asterisks.
    value: BaseExpression

    #: Optional keyword for the argument.
    keyword: Optional[Name] = None

    #: The equals sign used to denote assignment if there is a keyword.
    equal: Union[AssignEqual, MaybeSentinel] = MaybeSentinel.DEFAULT

def deep_equals(a: object, b: object) -> bool:
    if isinstance(a, CSTNode) and isinstance(b, CSTNode):
        return _deep_equals_cst_node(a, b)
    elif (
        isinstance(a, Sequence)
        and not isinstance(a, (str, bytes))
        and isinstance(b, Sequence)
        and not isinstance(b, (str, bytes))
    ):
        return _deep_equals_sequence(a, b)
    else:
        return a == b

def __init__(self) -> None:
        self.children: List[CSTNode] = []

with state.record_syntactic_position(self):
            self.target._codegen(state)
            self.operator._codegen(state)
            self.value._codegen(state)

        semicolon = self.semicolon
        if isinstance(semicolon, MaybeSentinel):
            if default_semicolon:
                state.add_token("; ")
        elif isinstance(semicolon, Semicolon):
            semicolon._codegen(state)


@add_slots
@dataclass(frozen=True)
class Decorator(CSTNode):
    """
    A single decorator that decorates a :class:`FunctionDef` or a :class:`ClassDef`.
    """

    #: The decorator that will return a new function wrapping the parent
    #: of this decorator.
    decorator: Union[Name, Attribute, Call]

    #: Line comments and empty lines before this decorator. The parent
    #: :class:`FunctionDef` or :class:`ClassDef` node owns leading lines before
    #: the first decorator so that if the first decorator is removed, spacing is preserved.
    leading_lines: Sequence[EmptyLine] = ()

    #: Whitespace after the ``@`` and before the decorator expression itself.
    whitespace_after_at: SimpleWhitespace = SimpleWhitespace.field("")

Colon,
    Comma,
    Dot,
    In,
    Is,
    IsNot,
    Not,
    NotIn,
)
from libcst._nodes.whitespace import BaseParenthesizableWhitespace, SimpleWhitespace
from libcst._visitors import CSTVisitorT


@add_slots
@dataclass(frozen=True)
class LeftSquareBracket(CSTNode):
    """
    Used by various nodes to denote a subscript or list section. This doesn't own
    the whitespace to the left of it since this is owned by the parent node.
    """

    #: Any space that appears directly after this left square bracket.
    whitespace_after: BaseParenthesizableWhitespace = SimpleWhitespace.field("")

    def _visit_and_replace_children(self, visitor: CSTVisitorT) -> "LeftSquareBracket":
        return LeftSquareBracket(
            whitespace_after=visit_required(
                self, "whitespace_after", self.whitespace_after, visitor
            )
        )

    def _codegen_impl(self, state: CodegenState) -> None:

state.add_token("except")
            self.whitespace_after_except._codegen(state)
            typenode = self.type
            if typenode is not None:
                typenode._codegen(state)
            namenode = self.name
            if namenode is not None:
                namenode._codegen(state)
            self.whitespace_before_colon._codegen(state)
            state.add_token(":")
            self.body._codegen(state)


@add_slots
@dataclass(frozen=True)
class Finally(CSTNode):
    """
    A ``finally`` clause that appears optionally after a :class:`Try` statement.
    """

    #: The body of the except.
    body: BaseSuite

    #: Sequence of empty lines appearing before this compound statement line.
    leading_lines: Sequence[EmptyLine] = ()

    #: The whitespace that appears after the ``finally`` keyword but before
    #: the colon.
    whitespace_before_colon: SimpleWhitespace = SimpleWhitespace.field("")

    def _visit_and_replace_children(self, visitor: CSTVisitorT) -> "Finally":
        return Finally(