keras/src/dtype_policies/dtype_policy.py/DTypePolicy/__init__
class DTypePolicy:    def __init__(self, name=None):
        # Use the global dtype policy if `name` is not specified
        if name is None:
            name = dtype_policy().name
        self._name = name
        self._compute_dtype, self._variable_dtype = self._parse_name(name)
        self._quantization_mode = None