code: @SuppressWarnings("static-method")
  	@Pure
  	@Inline(value = "$1.getCaller()", imported = Capacities.class, constantExpression = true)
  	protected AgentTrait getCaller() {
  		return Capacities.getCaller();
  	}
docs: Replies the caller of the capacity functions.
  
  <p>The replied value has a meaning inside the skills' functions that
  are implemented the capacities' functions.
  
  @return the caller, or {@code null} if the caller is unknown (assuming that the caller is the agent itself).
  @since 0.7