code: def maybe_get_common_dtype(arg_list):
      """Return common dtype of arg_list, or None.
  
      Args:
        arg_list: an iterable of items which are either `None` or have a `dtype`
          property.
  
      Returns:
        dtype: The common dtype of items in `arg_list`, or `None` if the list is
          empty or all items are `None`.
      """
      # Note that `all` defaults to `True` if `arg_list` is empty.
      if all(a is None for a in arg_list):
          return None
      return dtype_util.common_dtype(arg_list, tf.float32)
  
file_path: probability/tensorflow_probability/python/math/psd_kernels/internal/util.py
imports: import numpy
  import tensorflow.compat.v2
  from tensorflow_probability.python.internal import dtype_util
  from tensorflow_probability.python.internal import prefer_static
  from tensorflow_probability.python.internal import tensorshape_util
label_desc: Use image node_id 4 for calling a global function with example usage: maybe_get_common_dtype(arg_list) and returns: dtype_util, None