code: public static Selector expressionSelector(String expr, BeanFactory beanFactory) {
  		StandardEvaluationContext evalCtx = new StandardEvaluationContext();
  		if(null != beanFactory) {
  			evalCtx.setBeanResolver(new BeanFactoryResolver(beanFactory));
  		}
  		return expressionSelector(expr, evalCtx);
  	}
docs: Helper method for creating an {@code ExpressionSelector}.
  
  @param expr
  The expression to parse.
  @param beanFactory
  The {@link org.springframework.beans.factory.BeanFactory} to use to resolve references in the expression.
  
  @return A new {@link reactor.bus.selector.Selector}