import tensorflow as tf

    'The start warm-up learning rate to avoid NAN.')
tf.app.flags.DEFINE_integer(
    'warmup_steps', 100,
    'The total steps to warm-up.')
# for learning rate piecewise_constant decay
tf.app.flags.DEFINE_string(
    'decay_boundaries', '2, 3',
    'Learning rate decay boundaries by global_step (comma-separated list).')
tf.app.flags.DEFINE_string(
    'lr_decay_factors', '1, 0.5, 0.1',
    'The values of learning_rate decay factor for each segment between boundaries (comma-separated list).')
# checkpoint related configuration
tf.app.flags.DEFINE_string(
    'checkpoint_path', './model',
    'The path to a checkpoint from which to fine-tune.')
tf.app.flags.DEFINE_string(
