code: def is_vb(self):
      return self == LossType.KL or self == LossType.RESCALED_KL
  
imports: import enum
  import math
  import numpy
  import paddle
  from .losses import discretized_gaussian_log_likelihood
  from .losses import normal_kl
  from .nn import mean_flat
label_desc: Use image node_id 1 for calling the LossType obj's underlying member method code with example usage: obj.is_vb() and returns: unknown