docstr: Book instance of class openpyxl.workbook.Workbook.
  
  This attribute can be used to access engine-specific features.
docstr_tok: ["Book","instance","of","class","openpyxl.workbook.Workbook",".","This","attribute","can","be","used","to","access","engine-specific","features","."]
code: def book(self) -> Workbook:
      """
      Book instance of class openpyxl.workbook.Workbook.
  
      This attribute can be used to access engine-specific features.
      """
      return self._book
  
imports: from __future__ import annotations
  import mmap
  from typing import TYPE_CHECKING, Any, cast
  import numpy
  from pandas.compat._optional import import_optional_dependency
  from pandas.util._decorators import doc
  from pandas.core.shared_docs import _shared_docs
  from pandas.io.excel._base import BaseExcelReader, ExcelWriter
  from pandas.io.excel._util import combine_kwargs, validate_freeze_panes
label_desc: Use image node_id 2 for calling the OpenpyxlWriter obj's underlying member method code with example usage: obj.book() and returns: self