Googlecharts宝石 - 我在哪里放'require'gchart'

google.charts.load('current', {'packages':['corechart']});

google.charts.setOnLoadCallback(drawChart);

function drawChart() {
  var data = google.visualization.arrayToDataTable([
    ['Year', 'Sales', 'Expenses'],
    ['2004', 1000, 400],
    ['2005', 1170, 460],
    ['2006', 660, 1120],
    ['2007', 1030, 540]
  ]);

  var options = {
    title: 'Company Performance',
    curveType: 'function',
    legend: { position: 'bottom' }
  };

  var chart = new google.visualization.LineChart(document.getElementById('curve_chart'));

  chart.draw(data, options);
}