class_docstr: Element-wise sum of input arrays.
class_docstr_tok: ["Element-wise","sum","of","input","arrays","."]
code: def forward_gpu(self, inputs):
      ptrs = cuda.cupy.asarray(
          [x.data.ptr for x in inputs], dtype=cuda.cupy.int64
      )
      y = cuda.elementwise(
          "T x0, int64 xs, int32 n_xs",
          "T y",
          "float** xs_ = (float**) xs;"
          "y = 0;"
          "for (size_t j = 0; j < n_xs; ++j) {"
          "  y += xs_[j][i];"
          "}",
          "sum_arrays",
      )(inputs[0], ptrs.data.ptr, len(ptrs))
      return (y,)
  
file_path: chainerrl/chainerrl/functions/sum_arrays.py
imports: from chainer import cuda
  from chainer import function
  from chainer import utils
  from chainer.utils import type_check
label_desc: Use image node_id 4 for calling the SumArrays obj's underlying member method code with example usage: obj.forward_gpu(inputs) and returns: y