class_docstr: Test optimizers and related classes.
class_docstr_tok: ["Test","optimizers","and","related","classes","."]
docstr: test creating an optimizer with a PeiceWise constant decay to the learning rate
docstr_tok: ["test","creating","an","optimizer","with","a","PeiceWise","constant","decay","to","the","learning","rate"]
code: def test_PieceWise_decay_jax(self):
      """test creating an optimizer with a PeiceWise constant decay to the learning rate"""
      rate = optimizers.PiecewiseConstantSchedule(
          initial_rate=0.1,
          boundaries_and_scales={5000: 0.1, 10000: 0.1, 15000: 0.1},
      )
      opt = optimizers.Adam(learning_rate=rate)
      jaxopt = opt._create_jax_optimizer()
      assert isinstance(jaxopt, optax.GradientTransformation)
  
imports: import deepchem
  import deepchem.models.optimizers
  import unittest
  import pytest
label_desc: Use image node_id 27 for calling the TestOptimizers obj's underlying member method code with example usage: obj.test_PieceWise_decay_jax() without return types