Code in section 21.5: app$setValue() or app$setInputs()?

[youngroklee-ml]

In a code chunk, there is a line of code app$setValue(x = 2), but it returns an error.
Error in app$setValue(x = 2) : unused argument (x = 2)

I think it needs to be either app$setInputs(x = 2) or app$setValue("x", 2).

To experiment, I used this simple app:

library(shiny)
library(testthat)
library(shinytest)

ui <- fluidPage(
  numericInput("x", "x", value = 3, min = 1, max = 5),
  plotOutput("plot", width = "400px")
)
server <- function(input, output, session) {
  output$plot <- renderPlot(plot(seq_len(input$x)), res = 96)
}

app <- ShinyDriver$new(shinyApp(ui, server))