code: def inv_softplus(y):
      if y < 20.0:
          # y = log(1 + exp(x))  ==>  x = log(exp(y) - 1)
          return np.log(np.exp(y) - 1)
      else:
          return y
  
imports: import math
  from typing import Optional, Tuple
  import numpy
  from mxnet import gluon
  from gluonts.core.component import validated
  from gluonts.mx import Tensor
  from .distribution import Distribution, _sample_multiple, getF
  from .distribution_output import ArgProj, DistributionOutput, AffineTransformedDistribution
label_desc: Use image node_id 5 for calling a global function with example usage: inv_softplus(y) and returns: np, y