code: def Poisson(mu: vertex_constructor_param_types, label: Optional[str]=None) -> Vertex:
      
      return Integer(context.jvm_view().PoissonVertex, label, cast_to_double_vertex(mu))
docs: One to one constructor for mapping some shape of mu to
      a matching shaped Poisson.
      
      :param mu: mu with same shape as desired Poisson tensor or scalar