class AdamWeightDecayOptimizer(tf.train.Optimizer): AttributeError: 'module' object has no attribute 'Optimizer' code example

Example: class AdamWeightDecayOptimizer(tf.train.Optimizer): AttributeError: 'module' object has no attribute 'Optimizer'

pip uninstall tensorflow==2.2.0
pip install tensorflow==1.15.0
pip install bert-tensorflow