code: def test_simple():
      x = int64
      y = float32
      z = promote(x, y)
      assert z == float64
  
file_path: datashader/datashader/datashape/tests/test_promote.py
imports: import pytest
  from datashader.datashape import promote, Option, float64, int64, float32, optionify, string, datetime_, dshape
label_desc: Use image node_id 1 for calling a global function with example usage: test_simple() without return types