code: def mock_rasterize_func(df, x_range, y_range, height, width):
      cvs = ds.Canvas(
          x_range=x_range,
          y_range=y_range,
          plot_height=height,
          plot_width=width,
      )
      agg = cvs.points(df, "x", "y")
      return agg
  
file_path: datashader/datashader/tests/test_tiles.py
imports: from __future__ import annotations
  import datashader
  import datashader.transfer_functions
  from datashader.colors import viridis
  from datashader.tiles import render_tiles
  from datashader.tiles import gen_super_tiles
  from datashader.tiles import _get_super_tile_min_max
  from datashader.tiles import calculate_zoom_level_stats
  from datashader.tiles import MercatorTileDefinition
  import numpy
  import pandas
label_desc: Use image node_id 2 for calling a global function with example usage: mock_rasterize_func(df, x_range, y_range, height, width) and returns: agg