Spock Old Feature

StackSpec.groovy

import spock.lang.*

class StackSpec extends Specification {

  @Subject stack = new Stack()
	
  def "push a element into a stack"(element) {
    when:
    stack.push(element)
    then:
    stack.size() == old(stack.size()) + 1
    and:
    stack.contains(element)
    
    where:
    element = [name: "Tester"]
  }
}