code: def set_backend(name):
      """Sets the default backend to use in Trax."""
      if name:
          _assert_valid_backend_name(name)
      global default_backend
      default_backend = name
  
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 41 for calling a global function with example usage: set_backend(name) without return types