def get_node_or_fail(conn, node_id, coroutine=None, cargs=(), ckwargs={}):

    try:
        node = [node for node in conn.list_nodes()
                if str(node.id) == str(node_id)][0]
        return node
    except IndexError:
        if callable(coroutine):
            coroutine(*cargs, **ckwargs)
        return None
Shortcut to get a single node by its id. In case when 
dataset/ETHPy150Open novel/lc-tools/lctools/shortcuts.py/get_node_or_fail