def __init__(
      self,
      value: T,
      *,
      label: VariableLabel | None = None,
      metadata: dict[Any, Any] | None = None,
  ):
    """Constructs a new state variable.

    Args:
      value: The initial value of the variable.
      label: The unique label for this variable. If not provided, a unique label
        will be generated automatically.
      metadata: A dictionary of metadata associated with this Variable.
    """
    if label is None:
      label = _next_auto_variable_label(id(self))
    super().__init__(label=label, value=value, metadata=metadata)
Constructs a new state variable.

    Args:
      value: The initial value of the variable.
      label: The unique label for this variable. If not provided, a unique label
        will be generated automatically.
      metadata: A dictionary of metadata associated with this Variable.
    
penzai/core/variables.py