k$.extend() merges two JavaScript objects.

Here we have a "default" object, the employee. There are also two employee objects, alex and jesse.

var employee = {
  role: 'cashier',
  location: 'Atlanta, GA'
}

var alex = {
  name: 'Alex'
}

var jesse = {
  name: 'Jesse',
  role: 'CEO',
  location: 'NYC'
}

Let's see what happens when we extend employee to alex and jesse.

alex = k$.extend(employee, alex)

jesse = k$.extend(employee, jesse) 

Here's the output for each:

// alex

{
  role: 'cashier',
  location: 'Atlanta, GA',
  name: 'Alex'
}

// jesse

{
  role: 'CEO',
  location: 'NYC',
  name: 'Jesse'
}