code: def set_dtype_policy(policy):
      """Sets the default dtype policy globally.
  
      Example:
  
      >>> keras.mixed_precision.set_dtype_policy("mixed_float16")
      """
      if not isinstance(policy, DTypePolicy):
          if isinstance(policy, str):
              policy = DTypePolicy(policy)
          else:
              raise ValueError(
                  "Invalid `policy` argument. "
                  "Expected the string name of a policy "
                  "(such as 'mixed_float16') or a `DTypePolicy` "
                  f"instance. Received: policy={policy} "
                  f"(of type {type(policy)})"
              )
      global_state.set_global_attribute("dtype_policy", policy)
  
file_path: keras/keras/mixed_precision/dtype_policy.py
imports: from keras import backend
  from keras.api_export import keras_export
  from keras.backend.common import global_state
label_desc: Use image node_id 1 for calling a global function with example usage: set_dtype_policy(policy) without return types