old_contents: 
  # Copyright (c) 2016, The Bifrost Authors. All rights reserved.
  # Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
  #
  # Redistribution and use in source and binary forms, with or without
  # modification, are permitted provided that the following conditions
  # are met:
  # * Redistributions of source code must retain the above copyright
  #   notice, this list of conditions and the following disclaimer.
  # * Redistributions in binary form must reproduce the above copyright
  #   notice, this list of conditions and the following disclaimer in the
  #   documentation and/or other materials provided with the distribution.
  # * Neither the name of The Bifrost Authors nor the names of its
  #   contributors may be used to endorse or promote products derived
  #   from this software without specific prior written permission.
  #
  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
  # EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  # PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  # CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  # PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  # PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  # OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  from __future__ import absolute_import
  
  from .copy import copy, CopyBlock
  from .transpose import transpose, TransposeBlock
  from .fft import fft, FftBlock
  from .fftshift import fftshift, FftShiftBlock
  from .fdmt import fdmt, FdmtBlock
  from .detect import detect, DetectBlock
  from .guppi_raw import read_guppi_raw, GuppiRawSourceBlock
  from .sigproc import read_sigproc, SigprocSourceBlock
  from .audio import read_audio, AudioSourceBlock
  
new_contents: 
  # Copyright (c) 2016, The Bifrost Authors. All rights reserved.
  # Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
  #
  # Redistribution and use in source and binary forms, with or without
  # modification, are permitted provided that the following conditions
  # are met:
  # * Redistributions of source code must retain the above copyright
  #   notice, this list of conditions and the following disclaimer.
  # * Redistributions in binary form must reproduce the above copyright
  #   notice, this list of conditions and the following disclaimer in the
  #   documentation and/or other materials provided with the distribution.
  # * Neither the name of The Bifrost Authors nor the names of its
  #   contributors may be used to endorse or promote products derived
  #   from this software without specific prior written permission.
  #
  # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
  # EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  # PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  # CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  # PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  # PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  # OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  from __future__ import absolute_import
  
  from .copy import copy, CopyBlock
  from .transpose import transpose, TransposeBlock
  from .fft import fft, FftBlock
  from .fftshift import fftshift, FftShiftBlock
  from .fdmt import fdmt, FdmtBlock
  from .detect import detect, DetectBlock
  from .guppi_raw import read_guppi_raw, GuppiRawSourceBlock
  from .sigproc import read_sigproc, SigprocSourceBlock
  from .scrunch import scrunch, ScrunchBlock
  try: # Avoid error if portaudio library not installed
  	from .audio import read_audio, AudioSourceBlock
  except:
  	pass
  
subject: Add scrunch to blocks/__init__.py and avoid error if libportaudio not installed.