code: def forward(self, x):
      y, arg = _segment_reduce(self.op, x, self.offsets)
      self.save_for_backward(arg)
      return y
  
imports: import mxnet
  import numpy
  from mxnet import nd
  from ..._sparse_ops import _bwd_segment_cmp, _csrmask, _csrmm, _csrsum, _gsddmm, _gspmm, _scatter_add, _segment_reduce
  from ...base import ALL, dgl_warning, is_all
  from ...heterograph_index import create_unitgraph_from_csr
  from .tensor import asnumpy, context, copy_to, to_backend_ctx, zerocopy_from_numpy
label_desc: Use image node_id 2 for calling the SegmentReduce obj's underlying member method code with example usage: obj.forward(x) and returns: y