"description":"The command returns the number of messages successfully acknowledged. Certain message IDs may no longer be part of the PEL (for example because they have already been acknowledged), and XACK will not count them as successfully acknowledged.",
"description":"The ID of the added entry. The ID is the one auto-generated if * is passed as ID argument, otherwise the command just returns the same ID specified by the user during insertion.",
"type":"string",
"pattern":"[0-9]+-[0-9]+"
},
{
"description":"The NOMKSTREAM option is given and the key doesn't exist.",