There are two per-defined variables for your guard expression, workitem, target.
Schema for workitem:
{
"id":1,
"case_id":1,
"workflow_id":10,
"transition_id":24,
"state":"enabled",
"enabled_at":"2020-02-24T12:37:28.459Z",
"started_at":null,
"canceled_at":null,
"finished_at":null,
"overridden_at":null,
"deadline":null,
"created_at":"2020-02-24T12:37:28.601Z",
"updated_at":"2020-02-24T12:37:28.601Z",
"trigger_time":null,
"holding_user_id":null,
"children_count":3,
"children_finished_count":1,
"forked":false,
"parent_id":null,
"holding_user":{
},
"form":{
},
"children":[
{
"id":3,
"case_id":1,
"workflow_id":10,
"transition_id":24,
"state":"enabled",
"enabled_at":"2020-02-24T12:37:28.459Z",
"started_at":null,
"canceled_at":null,
"finished_at":null,
"overridden_at":null,
"deadline":null,
"created_at":"2020-02-24T12:37:28.757Z",
"updated_at":"2020-02-24T12:37:28.757Z",
"trigger_time":null,
"holding_user_id":"7",
"children_count":0,
"children_finished_count":0,
"forked":true,
"parent_id":1,
"holding_user":{
"id":7,
"name":"User6",
"created_at":"2020-02-24T12:36:46.994Z",
"updated_at":"2020-02-24T12:36:46.994Z",
"group_id":2
},
"form":{
},
"children":[
]
},
{
"id":4,
"case_id":1,
"workflow_id":10,
"transition_id":24,
"state":"enabled",
"enabled_at":"2020-02-24T12:37:28.459Z",
"started_at":null,
"canceled_at":null,
"finished_at":null,
"overridden_at":null,
"deadline":null,
"created_at":"2020-02-24T12:37:28.788Z",
"updated_at":"2020-02-24T12:37:28.788Z",
"trigger_time":null,
"holding_user_id":"5",
"children_count":0,
"children_finished_count":0,
"forked":true,
"parent_id":1,
"holding_user":{
"id":5,
"name":"User4",
"created_at":"2020-02-24T12:36:46.984Z",
"updated_at":"2020-02-24T12:36:46.984Z",
"group_id":1
},
"form":{
},
"children":[
]
},
{
"id":2,
"case_id":1,
"workflow_id":10,
"transition_id":24,
"state":"finished",
"enabled_at":"2020-02-24T12:37:28.459Z",
"started_at":null,
"canceled_at":null,
"finished_at":"2020-02-24T12:37:46.221Z",
"overridden_at":null,
"deadline":null,
"created_at":"2020-02-24T12:37:28.700Z",
"updated_at":"2020-02-24T12:37:46.232Z",
"trigger_time":null,
"holding_user_id":"1",
"children_count":0,
"children_finished_count":0,
"forked":true,
"parent_id":1,
"holding_user":{
"id":1,
"name":"User0",
"created_at":"2020-02-24T12:36:46.963Z",
"updated_at":"2020-02-24T12:36:46.963Z",
"group_id":4
},
"form":{
"score":90
},
"children":[
]
}
]
}