## group()


Several nodes to refresh together, against the same source versions:


Usage

``` python
group(*nodes)
```


`sv.group(a, b).refresh()`. A stored node they share is refreshed and written once; `.status()` reports on each.


## Parameters


`*nodes: Node`  
The nodes to refresh together: results of transforms, stored or not (not sources).


## Returns


`Group`  
A [Group](nodes.Group.md#sverify.nodes.Group), with [refresh](Node.refresh.md#sverify.Node.refresh) and [status](Node.status.md#sverify.Node.status).


## Raises


`TypeError`  
No nodes are given, or one is not a node (a source, or an Ibis table).


## Examples

Two outputs that read the same stored node, with `p` and `r` from the [Node](Node.md#sverify.Node) example:

``` python
@sv.transform()
def customers(t):
    return t.select(t.customer)

g = sv.group(r, p.pipe(customers))  # fan-out: p is piped twice
result = g.refresh()  # paid is refreshed and written once
[s.node for s in result.nodes]  # ['paid', 'doubled', 'customers']
print(g.status())  # one line per node
```