liquid null check

In Objective-C, you can perform a null check using the != operator to compare a variable to nil. Here's an example:

if (myVariable != nil) {
    // Code to execute if myVariable is not nil
} else {
    // Code to execute if myVariable is nil

This code checks if the variable myVariable is not equal to nil. If it is not nil, the code inside the first block will be executed. Otherwise, the code inside the else block will be executed.

Please note that the code snippet provided is a general example, and you may need to adapt it to your specific use case.