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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def CreateGroup(r, name, alloc_policy=None, dry_run=False):
 """ Creates a new node group. @type name: str @param name: the name of node group to create @type alloc_policy: str @param alloc_policy: the desired allocation policy for the group, if any @type dry_run: bool @param dry_run: whether to peform a dry run @rtype: int @return: job id """


    query = {
        "dry-run": dry_run,
    }

    body = {
        "name": name,
        "alloc_policy": alloc_policy
    }

    return r.request("post", "/2/groups", query=query, content=body)