docstr: Index along the major axis where idx is an array of ints.
          
code: def _major_index_fancy(self, idx):
      """Index along the major axis where idx is an array of ints."""
      _, N = self._swap(*self.shape)
      M = idx.size
      new_shape = self._swap(M, N)
      if self.nnz == 0 or M == 0:
          return self.__class__(new_shape, dtype=self.dtype)
  
      return self.__class__(
          _index._csr_row_index(
              self.data, self.indices, self.indptr, idx
          ),
          shape=new_shape,
          copy=False,
      )
  
imports: import string
  import warnings
  import numpy
  import cupy
  import cupyx
  from cupy import _core
  from cupy._core import _scalar
  from cupy._creation import basic
  from cupyx.scipy.sparse import _base
  from cupyx.scipy.sparse import _coo
  from cupyx.scipy.sparse import _data
  from cupyx.scipy.sparse import _sputils
  from cupyx.scipy.sparse import _util
  from cupyx.scipy.sparse import _index
label_desc: Use image node_id 15 for calling the _compressed_sparse_matrix obj's underlying member method code with example usage: obj._major_index_fancy(idx) and returns: self, self