Download a list of layers to the cache

        Parameters
        ----------
        layers list(samcli.commands.local.lib.provider.Layer)
            List of Layers representing the layer to be downloaded
        force bool
            True to download the layer even if it exists already on the system

        Returns
        -------
        List(Path)
            List of Paths to where the layer was cached

def download_all(self, layers, force=False):
        """
        Download a list of layers to the cache

        Parameters
        ----------
        layers list(samcli.commands.local.lib.provider.Layer)
            List of Layers representing the layer to be downloaded
        force bool
            True to download the layer even if it exists already on the system

        Returns
        -------
        List(Path)
            List of Paths to where the layer was cached
        """
        layer_dirs = []
        for layer in layers:
            layer_dirs.append(self.download(layer, force))

        return layer_dirs