def __init__(
        self, name, elem_type=None, init_length=None, dynamic_length=True, sym_val=None, **kwargs
    ):
        """
        elem_type (builtin.tensor)

        init_length (int): initial length

        dynamic_length (bool): True to allow list to grow. False uses
        init_length as the fixed size (init_length is runtime length).

        sym_val: value of the list, if available
        """
        super().__init__(
            name=name,
            sym_type=types.list(elem_type, init_length, dynamic_length),
            sym_val=sym_val,
            **kwargs
        )
        self._elem_type = elem_type
        self.init_length = init_length
        self.dynamic_length = dynamic_length

        elem_type (builtin.tensor)

        init_length (int): initial length

        dynamic_length (bool): True to allow list to grow. False uses
        init_length as the fixed size (init_length is runtime length).

        sym_val: value of the list, if available
        
coremltools/converters/mil/mil/var.py