def layer_uri(self, layer_name):
        """Get layer URI.

        :param layer_name: The name of the layer to fetch.
        :type layer_name: str

        :return: The URI to the layer.
        :rtype: str

        .. versionadded:: 4.0
        """
        layers = self.layers()
        for layer, extension in product(layers, EXTENSIONS):
            one_file = QFileInfo(
                self.uri.filePath(layer + '.' + extension))
            if one_file.exists():
                if one_file.baseName() == layer_name:
                    return one_file.absoluteFilePath()
        else:
            return None
Get layer URI.

        :param layer_name: The name of the layer to fetch.
        :type layer_name: str

        :return: The URI to the layer.
        :rtype: str

        .. versionadded:: 4.0