code: def test_array_subarray():
      assert datashape.dshape("3 * int32").subarray(
          0
      ) == datashape.dshape("3 * int32")
      assert datashape.dshape("3 * int32").subarray(
          1
      ) == datashape.DataShape(datashape.int32)
      assert str(
          datashape.dshape("3 * var * M * int32").subarray(2)
      ) == str(datashape.dshape("M * int32"))
      assert str(
          datashape.dshape("3 * var * M * float64").subarray(3)
      ) == str(datashape.float64)
  
imports: from datashader import datashape
  import pytest
label_desc: Use image node_id 2 for calling a global function with example usage: test_array_subarray() without return types