code: def heatmap(z, x=None, y=None, colorscale='Viridis'):
      
      z = np.atleast_1d(z)
      data = [go.Heatmap(z=z, x=x, y=y, colorscale=colorscale)]
      return Chart(data=data)
docs: Create a heatmap.
  
      Parameters
      ----------
      z : TODO
      x : TODO, optional
      y : TODO, optional
      colorscale : TODO, optional
  
      Returns
      -------
      Chart