Validate on professional data.

def validate_pro():
    """Validate on professional data."""
    cmd = ['python3', 'validate.py', FLAGS.pro_dataset,
           '--use_tpu',
           '--tpu_name={}'.format(TPU_NAME),
           '--work_dir={}'.format(fsdb.working_dir()),
           '--flagfile=rl_loop/distributed_flags',
           '--validate_name=pro']
    mask_flags.run(cmd)