code: def test_pan_callbacks() -> None:
      plot = Plot()
      payload = dict(sx=3, sy=-2, x=10, y=100, delta_x=2, delta_y=3.2)
      test_callback = EventCallback(
          ["sx", "sy", "x", "y", "delta_x", "delta_y"]
      )
      plot.on_event(events.Pan, test_callback)
      assert test_callback.event_name is None
      plot._trigger_event(events.Pan(plot, **payload))
      assert test_callback.event_name == events.Pan.event_name
      assert test_callback.payload == payload
  
imports: from __future__ import annotations
  import pytest
  from bokeh.core.serialization import Deserializer
  from bokeh.models import Button, Div, Plot, TextInput
  from bokeh import events
label_desc: Use image node_id 32 for calling a global function with example usage: test_pan_callbacks() without return types