code: def _get_test_datasets_3d():
      """Create a single 3D test dataset."""
      from pyresample.geometry import AreaDefinition
  
      adef = AreaDefinition(
          "test",
          "test",
          "test",
          "EPSG:4326",
          100,
          200,
          (-180.0, -90.0, 180.0, 90.0),
      )
      ds1 = xr.DataArray(
          da.zeros((3, 100, 200), chunks=50),
          dims=("bands", "y", "x"),
          coords={"bands": ["R", "G", "B"]},
          attrs={
              "name": "test",
              "start_time": datetime.utcnow(),
              "area": adef,
          },
      )
      return [ds1]
  
imports: from datetime import datetime
  from unittest import mock
  import dask.array
  import numpy
  import pytest
  import xarray
label_desc: Use image node_id 3 for calling a global function with example usage: _get_test_datasets_3d() and returns: list