code: def setUp(self):
      self.function = getattr(functions, self.function_name)
  
      self.x = numpy.random.uniform(-1, 1, (3, 2, 4)).astype(
          numpy.float32
      )
  
imports: import unittest
  import numpy
  import chainer
  from chainer import functions
  from chainer import testing
  from chainer import utils
label_desc: Use image node_id 1 for calling the TestArgMinMaxInvalid obj's underlying member method code with example usage: obj.setUp() without return types