docstr: Sets value at each (i, j) to x
  Here (i,j) index major and minor respectively, and must not contain
  duplicate entries.
code: def _set_many(self, i, j, x):
      """Sets value at each (i, j) to x
      Here (i,j) index major and minor respectively, and must not contain
      duplicate entries.
      """
      i, j, M, N = self._prepare_indices(i, j)
      x = cupy.array(x, dtype=self.dtype, copy=True, ndmin=1).ravel()
  
      new_sp = cupyx.scipy.sparse.csr_matrix(
          (
              cupy.arange(self.nnz, dtype=cupy.float32),
              self.indices,
              self.indptr,
          ),
          shape=(M, N),
      )
  
      offsets = (
          new_sp._get_arrayXarray(i, j, not_found_val=-1)
          .astype(cupy.int32)
          .ravel()
      )
  
      mask = offsets > -1
      self.data[offsets[mask]] = x[mask]
  
      if mask.all():
          # only affects existing non-zero cells
          return
  
      # only insertions remain
      warnings.warn(
          "Changing the sparsity structure of a "
          "{}_matrix is expensive.".format(self.format),
          _base.SparseEfficiencyWarning,
      )
      mask = ~mask
      i = i[mask]
      i[i < 0] += M
      j = j[mask]
      j[j < 0] += N
      self._insert_many(i, j, x[mask])
  
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 23 for calling the _compressed_sparse_matrix obj's underlying member method code with example usage: obj._set_many(i, j, x) without return types