class_docstr: Mixin class for Dataset types that provide an interface
  to a HDF5 group, e.g `DatasetList`, `DatasetDict`. Provides
  a `_mapper` property over the type's ``bind`` attribute.
class_docstr_tok: ["Mixin","class","for","Dataset","types","that","provide","an","interface","to","a","HDF5","group",",","e.g","`","DatasetList","`",",","`","DatasetDict","`",".","Provides","a","`","_mapper","`","property","over","the","type","'s","``","bind","``","attribute","."]
code: def _mapper(self) -> AttributeTypeMapper:
      if self.__mapper is None:
          self.__mapper = AttributeTypeMapper(self.bind)
  
      return self.__mapper
  
imports: import typing
  from collections.abc import MutableMapping
  from types import MappingProxyType
  from typing import Any, Dict, Optional, Type
  from pennylane.data.base.attribute import AttributeInfo, DatasetAttribute, get_attribute_type, match_obj_type
  from pennylane.data.base.hdf5 import HDF5Any, HDF5Group
label_desc: Use image node_id 1 for calling the MapperMixin obj's underlying member method code with example usage: obj._mapper() and returns: self