code: def h2o_H2OFrame_which():
      """
      Python API test: h2o.frame.H2OFrame.which()
      """
      python_lists = np.random.randint(1, 5, (100, 1))
      h2oframe = h2o.H2OFrame(python_obj=python_lists)
      newFrame = h2oframe.which()  # first row contains index 0.
  
      assert_is_type(newFrame, H2OFrame)  # check return type
      assert newFrame[
          1 : h2oframe.nrow, 0
      ].all(), "h2o.H2OFrame.which() command is not working."
  
imports: import sys
  import h2o
  from tests import pyunit_utils
  from h2o.utils.typechecks import assert_is_type
  import numpy
  from h2o.frame import H2OFrame
label_desc: Use image node_id 1 for calling a global function with example usage: h2o_H2OFrame_which() without return types