code: def main():
      fig = plt.figure()
  
      # Setup a global EckertIII map with faint coastlines.
      ax = fig.add_subplot(1, 1, 1, projection=ccrs.EckertIII())
      ax.set_global()
      ax.coastlines("110m", alpha=0.1)
  
      # Use the same sample data as the waves example, but make it
      # more dependent on y for more interesting contours.
      x, y, z = sample_data((20, 40))
      z = z * -1.5 * y
  
      # Add colourful filled contours.
      filled_c = ax.contourf(x, y, z, transform=ccrs.PlateCarree())
  
      # And black line contours.
      line_c = ax.contour(
          x,
          y,
          z,
          levels=filled_c.levels,
          colors=["black"],
          transform=ccrs.PlateCarree(),
      )
  
      # Uncomment to make the line contours invisible.
      # plt.setp(line_c.collections, visible=False)
  
      # Add a colorbar for the filled contour.
      fig.colorbar(filled_c, orientation="horizontal")
  
      # Use the line contours to place contour labels.
      ax.clabel(
          line_c,  # Typically best results when labelling line contours.
          colors=["black"],
          manual=False,  # Automatic placement vs manual placement.
          inline=True,  # Cut the line where the label will be placed.
          fmt=" {:.0f} ".format,  # Labes as integers, with some extra space.
      )
  
      plt.show()
  
imports: import matplotlib.pyplot
  import cartopy.crs
label_desc: Use image node_id 2 for calling a global function with example usage: main() without return types