code: def _update_default_dtypes():
      """Update default dtype of functions.
  
      How it works?
      -------------
      "dtype" is updated in __defaults__ or __kwdefaults__ to default dtype.
  
      Every time default dtype is changed, all the functions that follow this
      strategy will have their default dtype updated.
  
      It (mutably) changes function defaults. For external functions, copy the
      function first to avoid surprising users.
      """
      for func in _TO_UPDATE_FUNCS_DTYPE:
          pos = _get_dtype_pos_in_defaults(func)
          defaults = list(func.__defaults__)
          defaults[pos] = _config.DEFAULT_DTYPE
          func.__defaults__ = tuple(defaults)
  
      for func in _TO_UPDATE_FUNCS_KW_DTYPE:
          func.__kwdefaults__["dtype"] = _config.DEFAULT_DTYPE
  
file_path: geomstats/geomstats/_backend/_dtype_utils.py
imports: import functools
  import inspect
  import types
  from geomstats._backend import _backend_config
label_desc: Use image node_id 3 for calling a global function with example usage: _update_default_dtypes() without return types