old_contents: # abstract base class
  from pyro.distributions.bernoulli import Bernoulli
  from pyro.distributions.beta import Beta
  from pyro.distributions.categorical import Categorical
  from pyro.distributions.delta import Delta
  from pyro.distributions.distribution import Distribution
  # specific distributions
  from pyro.distributions.diag_normal import DiagNormal
  from pyro.distributions.dirichlet import Dirichlet
  from pyro.distributions.exponential import Exponential
  from pyro.distributions.gamma import Gamma
  from pyro.distributions.log_normal import LogNormal
  from pyro.distributions.multinomial import Multinomial
  from pyro.distributions.normal import Normal
  from pyro.distributions.normal_chol import NormalChol
  from pyro.distributions.poisson import Poisson
  from pyro.distributions.uniform import Uniform
  
  # function aliases
  diagnormal = DiagNormal()
  lognormal = LogNormal()
  categorical = Categorical()
  bernoulli = Bernoulli()
  beta = Beta()
  delta = Delta()
  exponential = Exponential()
  gamma = Gamma()
  multinomial = Multinomial()
  normal = Normal()
  normalchol = NormalChol()
  poisson = Poisson()
  uniform = Uniform()
  dirichlet = Dirichlet()
  
new_contents: # abstract base class
  from pyro.distributions.bernoulli import Bernoulli
  from pyro.distributions.beta import Beta
  from pyro.distributions.categorical import Categorical
  from pyro.distributions.delta import Delta
  from pyro.distributions.distribution import Distribution  # noqa: F401
  # specific distributions
  from pyro.distributions.diag_normal import DiagNormal
  from pyro.distributions.dirichlet import Dirichlet
  from pyro.distributions.exponential import Exponential
  from pyro.distributions.gamma import Gamma
  from pyro.distributions.log_normal import LogNormal
  from pyro.distributions.multinomial import Multinomial
  from pyro.distributions.normal import Normal
  from pyro.distributions.normal_chol import NormalChol
  from pyro.distributions.poisson import Poisson
  from pyro.distributions.uniform import Uniform
  
  # function aliases
  diagnormal = DiagNormal()
  lognormal = LogNormal()
  categorical = Categorical()
  bernoulli = Bernoulli()
  beta = Beta()
  delta = Delta()
  exponential = Exponential()
  gamma = Gamma()
  multinomial = Multinomial()
  normal = Normal()
  normalchol = NormalChol()
  poisson = Poisson()
  uniform = Uniform()
  dirichlet = Dirichlet()
  
subject: add exception for distribution