code: def test_basic(self) -> None:
      t = bt.linear_cmap(
          "foo",
          ["red", "green"],
          0,
          10,
          low_color="orange",
          high_color="blue",
          nan_color="pink",
      )
      assert isinstance(t, Field)
      assert t.field == "foo"
      assert isinstance(t.transform, LinearColorMapper)
      assert t.transform.palette == ["red", "green"]
      assert t.transform.low == 0
      assert t.transform.high == 10
      assert t.transform.low_color == "orange"
      assert t.transform.high_color == "blue"
      assert t.transform.nan_color == "pink"
  
imports: from __future__ import annotations
  import pytest
  from bokeh.core.property.vectorization import Expr, Field
  from bokeh.models import CategoricalColorMapper, CategoricalMarkerMapper, CategoricalPatternMapper, CumSum, Dodge, EqHistColorMapper, FactorRange, Jitter, LinearColorMapper, LogColorMapper, Stack
  from tests.support.util.api import verify_all
  import bokeh.transform
label_desc: Use image node_id 1 for calling the Test_linear_cmap obj's underlying member method code with example usage: obj.test_basic() without return types