<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def Query(r, what, fields, qfilter=None):
 """ Retrieves information about resources. @type what: string @param what: Resource name, one of L{constants.QR_VIA_RAPI} @type fields: list of string @param fields: Requested fields @type qfilter: None or list @param qfilter: Query filter @rtype: string @return: job id """


    body = {
        "fields": fields,
    }

    if qfilter is not None:
        body["qfilter"] = body["filter"] = qfilter

    return r.request("put", "/2/query/%s" % what, content=body)