def get(tree, node, verify=True):
    """Retrieve the manifest instance for a given directory and binary node.

        ``node`` always refers to the node of the root manifest (which will be
        the only manifest if flat manifests are being used).

        If ``tree`` is the empty string, the root manifest is returned.
        Otherwise the manifest for the specified directory will be returned
        (requires tree manifests).

        If ``verify`` is True, ``LookupError`` is raised if the node is not
        known.

        The returned object conforms to the ``imanifestrevisionstored``
        interface.
        """
