code: public void setEngineValves(Collection<? extends Valve> engineValves) {
  		Assert.notNull(engineValves, "Valves must not be null");
  		this.engineValves = new ArrayList<>(engineValves);
  	}
docs: Set {@link Valve}s that should be applied to the Tomcat {@link Engine}. Calling
  this method will replace any existing valves.
  @param engineValves the valves to set