class_docstr: Tests SignalConv against scipy.signal.
class_docstr_tok: ["Tests","SignalConv","against","scipy.signal","."]
code: def data_formats(self):
      # On CPU, many ops don't support the channels first data format. Hence, if
      # no GPU is available, we skip these tests.
      if tf.config.experimental.list_physical_devices("GPU"):
          return ("channels_first", "channels_last")
      else:
          return ("channels_last",)
  
imports: import os
  from absl.testing import parameterized
  import numpy
  import scipy.signal
  import tensorflow
  from tensorflow_compression.python.layers import initializers
  from tensorflow_compression.python.layers import parameters
  from tensorflow_compression.python.layers import signal_conv
label_desc: Use image node_id 6 for calling the ConvolutionsTest obj's underlying member method code with example usage: obj.data_formats() and returns: str,  str, str