如何在R Shiny中更改google气泡图的播放速度？

library(shiny)
library(googleVis)

ui <- fluidPage(
  tags$head(
    tags$script(src = "https://www.gstatic.com/charts/loader.js"),
    tags$script("
      google.charts.load('current', {'packages':['motionchart']});
      google.charts.setOnLoadCallback(drawChart);
      
      function drawChart() {
        var data = new google.visualization.DataTable();
        data.addColumn('string', 'Country');
        data.addColumn('date', 'Year');
        data.addColumn('number', 'Population');
        data.addColumn('number', 'GDP');
        data.addColumn('number', 'Life Expectancy');
        
        // Add data rows here
        
        var options = {
          width: '100%',
          height: '400px',
          animation: {
            duration: 1000, // 设置动画持续时间为1秒
            easing: 'in'
          }
        };
        
        var chart = new google.visualization.MotionChart(document.getElementById('chart_div'));
        chart.draw(data, options);
      }
    ")
  ),
  fluidRow(
    column(width = 12, div(id = "chart_div"))
  )
)

server <- function(input, output) {
  # Server logic here
}

shinyApp(ui = ui, server = server)