class_docstr: Data in the buffer is guaranteed to be contiguous in memory.
  
  Note that there is no dtype attribute present, a buffer can be thought of
  as simply a block of memory. However, if the column that the buffer is
  attached to has a dtype that's supported by DLPack and ``__dlpack__`` is
  implemented, then that dtype information will be contained in the return
  value from ``__dlpack__``.
  
  This distinction is useful to support both data exchange via DLPack on a
  buffer and (b) dtypes like variable-length strings which do not have a
  fixed number of bytes per element.
docstr: Device type and device ID for where the data in the buffer resides.
  Uses device type codes matching DLPack.
  Note: must be implemented even if ``__dlpack__`` is not.
code: def __dlpack_device__(self) -> tuple[DlpackDeviceType, int | None]:
      """
      Device type and device ID for where the data in the buffer resides.
      Uses device type codes matching DLPack.
      Note: must be implemented even if ``__dlpack__`` is not.
      """
      if self._x.is_cpu:
          return (DlpackDeviceType.CPU, None)
      else:
          raise NotImplementedError("__dlpack_device__")
  
file_path: arrow/python/pyarrow/interchange/buffer.py
imports: from __future__ import annotations
  import enum
  import pyarrow
label_desc: Use image node_id 5 for calling the _PyArrowBuffer obj's underlying member method code with example usage: obj.__dlpack_device__() and returns: DlpackDeviceType,  None