title: Python Folium HeatMapWithTime: one time slider across multiple data layers
body: <p>Since I am using the same index variable with default time slider parameters for both data layers, I expect the HeatMapWithTime to only produce one time slider. However, that is not the case as it adds extra time slider for each layer. This becomes an issue when you have let's say 10 different data layers and 10 identical time sliders on the side of your map.</p>
  
  <pre><code>heatmap = folium.Map(location=[0, 0], zoom_start=1.5)
  HeatMapWithTime(data_1,index=index,overlay=False).add_to(heatmap)
  HeatMapWithTime(data_2,index=index,overlay=False).add_to(heatmap)
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/Z5YJA.png" rel="nofollow noreferrer">Output screenshot: multiple identical time sliders</a></p>
  
  <p>If index variable and time slider parameters are set to be the same across different data layers, the map should only produce one time slider right?</p>
  
  <p>Update:</p>
  
  <p>I just found multiple layer example with one time slider using TimestampedWmsTileLayers on <a href="https://nbviewer.jupyter.org/github/python-visualization/folium/blob/master/examples/WmsTimeDimension.ipynb" rel="nofollow noreferrer">nbviewer</a>. How can this be re-created using HeatMapWithTime??</p>