class_docstr: Backend providing random functions.
class_docstr_tok: ["Backend","providing","random","functions","."]
code: def get_prng(self, seed):
      return backend()["random_get_prng"](seed)
  
imports: import contextlib
  import enum
  import gin
  from trax.fastmath.jax import JAX_BACKEND
  from trax.fastmath.numpy import NUMPY_BACKEND
  from trax.fastmath.tf import TF_BACKEND
label_desc: Use image node_id 1 for calling the RandomBackend obj's underlying member method code with example usage: obj.get_prng(seed) and returns: backend