# Expensive Operations
## Instructions
Add an output parameter of `command = delay` to any output node. Leopard will then show the "thinking" graphic until it next receives a response from Teneo. When the graphic is shown Teneo automatically sends back an empty input to Teneo with a request parameter of `command=continue` . You can then begin your expensive operation and return the response as per usual.
Remember you can retrieve request parameters in Teneo in Pre-Processing.
{% code title="Pre-Processing script grabs command parameter and sets it as a global variable" %}
```groovy
if (engineEnvironment.getParameter("command")) {
command = engineEnvironment.getParameter("command")
} else {
command = ""
}
```
{% endcode %}
### Screenshots
### Output Parameter
```
command = delay
```
##
