Revert "Remove pickling until pickle PR.":

This commit is also in the fix-encoders test. The reason it wasn't used
it because the mocker framework was being re-done in this commit. So its
just sitting here in both unused. And at this point, modifying
fix-encoder might provoke git to forget about conflicts already
resolved.

This reverts commit 94df9ac.

Author: ayjayt

src/py/integration_tests/dates/__init__.py

@@ -0,0 +1 @@
+"""These are really just scripts, run them as such. Include pickle dev group."""

src/py/integration_tests/dates/figs/scatter_map_w_layers.pkl.zst

@@ -0,0 +1,58 @@
+"""Create pickled fig for use in integration tests."""
+
+import pickle
+from pathlib import Path
+
+import datashader as ds
+import datashader.transfer_functions as tf
+import pandas as pd
+import plotly.express as px
+import zstandard as zstd
+from colorcet import fire
+
+cctx = zstd.ZstdCompressor(level=20)
+
+df = pd.read_csv(
+    "https://raw.githubusercontent.com/plotly/datasets/master/uber-rides-data1.csv",
+)
+dff = (
+    df.query("Lat < 40.82")
+    .query("Lat > 40.70")
+    .query("Lon > -74.02")
+    .query("Lon < -73.91")
+)
+
+
+cvs = ds.Canvas(plot_width=1000, plot_height=1000)
+agg = cvs.points(dff, x="Lon", y="Lat")
+# agg is an xarray object, see http://xarray.pydata.org/en/stable/ for more details
+coords_lat, coords_lon = agg.coords["Lat"].to_numpy(), agg.coords["Lon"].to_numpy()
+# Corners of the image
+coordinates = [
+    [coords_lon[0], coords_lat[0]],
+    [coords_lon[-1], coords_lat[0]],
+    [coords_lon[-1], coords_lat[-1]],
+    [coords_lon[0], coords_lat[-1]],
+]
+
+
+img = tf.shade(agg, cmap=fire)[::-1].to_pil()
+
+
+# Trick to create rapidly a figure with map axes
+fig = px.scatter_map(dff[:1], lat="Lat", lon="Lon", zoom=12)
+# Add the datashader image as a tile map layer image
+fig.update_layout(
+    map_style="carto-darkmatter",
+    map_layers=[{"sourcetype": "image", "source": img, "coordinates": coordinates}],
+)
+
+raw = pickle.dumps(fig, protocol=5)  # >=3.8
+compressed = cctx.compress(raw)
+with Path(f"./figs/{Path(__file__).stem}.pkl.zst").open("wb") as f:
+    f.write(compressed)
+
+print(  # noqa: T201
+    f"{Path(__file__).stem}.pkl: "
+    f"{len(raw) / 1024:.1f} -> {len(compressed) / 1024:.1f} KB",
+)