code: def test_reconstructions_are_lossless(self, n_t, stride):
      n_batch = 2
      n_ch = 3
      x = tf.tile(
          tf.reshape(tf.range(n_t), [1, n_t, 1]), [n_batch, 1, n_ch]
      )
      x_down = nn.polyphase_resample(
          x, stride, "down", trim_or_pad="pad"
      )
      x_recon = nn.polyphase_resample(
          x_down, stride, "up", trim_or_pad="pad"
      )
      self.assertAllEqual(x, x_recon)
  
imports: from absl.testing import parameterized
  from ddsp.training import nn
  import numpy
  import tensorflow.compat.v2
label_desc: Use image node_id 1 for calling the PolyphaseResampleTest obj's underlying member method code with example usage: obj.test_reconstructions_are_lossless(n_t, stride) without return types