class_docstr: Sum of array elements over a given axis.
code: def forward_chainerx(self, inputs):
      (x,) = inputs
      return (chainerx.sum(x, axis=self.axis, keepdims=self.keepdims),)
  
imports: import numpy
  import six
  import chainer
  from chainer import backend
  from chainer import function_node
  from chainer import utils
  from chainer.utils import type_check
  import chainerx
label_desc: Use image node_id 3 for calling the Sum obj's underlying member method code with example usage: obj.forward_chainerx(inputs) and returns: chainerx