`float`, *optional*, defaults to 0.02):
            The standard deviation of the truncated_normal_initializer for initializing all weight matrices.
        layer_norm_eps (`float`, *optional*, defaults to 1e-12):
            The epsilon used by the layer normalization layers.
        attention_window (`int` or `List[int]`, *optional*, defaults to 512):
            Size of an attention window around each token. If an `int`, use the same size for all layers. To specify a
            different window size for each layer, use a `List[int]` where `len(attention_window) == num_hidden_layers`.

    Example:

    ```python
    >>> from transformers import LongformerConfig, LongformerModel

    >>> # Initializing a Longformer configuration
    >>> configuration = LongformerConfig()

    >>> # Initializing a model from the configuration
    >>> model = LongformerModel(configuration)

    >>> # Accessing the model configuration
    >>> configuration = model.config
    ```Z
longformer