code: def forward(self, x):
      self.retain_inputs((0, 1))
      a, b = x
      return (_batch_matmul(a, b, self.transa, self.transb, False),)
  
imports: import warnings
  import numpy
  from chainer import backend
  from chainer.backends import cuda
  from chainer import function_node
  import chainer.functions
  from chainer import utils
  from chainer.utils import type_check
  import chainerx
label_desc: Use image node_id 3 for calling the BatchMatMul obj's underlying member method code with example usage: obj.forward(x) and returns: _batch_matmul