class_docstr: This class provides common dispatching and validation logic for indexing.
code: def _is_scalar(self, index):
      if (
          isinstance(index, (cupy.ndarray, numpy.ndarray))
          and index.ndim == 0
          and index.size == 1
      ):
          return True
      return False
  
imports: import cupy
  from cupy import _core
  from cupyx.scipy.sparse._base import isspmatrix
  from cupyx.scipy.sparse._base import spmatrix
  from cupy.cuda import device
  from cupy.cuda import runtime
  import numpy
label_desc: Use image node_id 3 for calling the IndexMixin obj's underlying member method code with example usage: obj._is_scalar(index) and returns: False, True