Default Variables are special variables that can not be overridden. You can use them just like any other variables.
$parent
- a reference to a parent node;
$prevStep
- a reference to the previous node within a Folder node;
$nextStep
- a reference to the next node within a Folder node;
$dynamicVar
- a dynamic variables object;
$response
- a reference to a response in a RequestStep node;
$env
- an environment variables object.
$systemVar
- an object for accessing system environment variables
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