# Activation boxes
# ----------------

me : actor
you : Class
them : Class

# What it represents:
# - The period during which an object is "active" or "busy"
# - When an object is executing a method, processing data, or performing some operation
# - The duration of control focus on that particular object

ref( Sequence Diagrams | /diagrams/uml-sequence-diagrams )
you.start() {
  them.get() {
    you.check()
  }
}

note(260,100,300,A UML sequence diagram activation box (also called an execution specification\) is a narrow rectangular box that appears on an object's lifeline to show when that object is actively executing code or processing a request.)

# Key behaviors:
# - Starts when the object receives a message and begins processing
# - Ends when the object finishes processing and potentially sends a return message
# - Can be nested - one activation box can contain others if the object calls other methods during its execution
# - Multiple activation boxes can appear on the same lifeline for different method calls