code: def setUp(self):
      CTCTestBase.setUp(self)
      self.x = numpy.random.uniform(-1, 1, (4, 2, 4)).astype(self.dtype)
      self.l = numpy.array([[3, 0, 3, 1, 3], [3, 1, 3, 0, 3]]).astype(
          numpy.int32
      )
      self.blank_symbol = 3
  
imports: import math
  import unittest
  import numpy
  import chainer
  from chainer import backend
  from chainer.backends import cuda
  from chainer import functions
  from chainer import gradient_check
  from chainer import testing
  from chainer.testing import attr
  from chainer.testing import condition
label_desc: Use image node_id 1 for calling the TestCTCBlankSymbol obj's underlying member method code with example usage: obj.setUp() without return types