text: #!/usr/bin/env python
  
  #  Copyright (c) 2005 Gavin E. Crooks <gec@threeplusone.com>
  #
  #  This software is distributed under the MIT Open Source License.
  #  <http://www.opensource.org/licenses/mit-license.html>
  #
  #  Permission is hereby granted, free of charge, to any person obtaining a 
  #  copy of this software and associated documentation files (the "Software"),
  #  to deal in the Software without restriction, including without limitation
  #  the rights to use, copy, modify, merge, publish, distribute, sublicense,
  #  and/or sell copies of the Software, and to permit persons to whom the
  #  Software is furnished to do so, subject to the following conditions:
  #
  #  The above copyright notice and this permission notice shall be included
  #  in all copies or substantial portions of the Software.
  #
  #  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
  #  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
  #  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  #  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
  #  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  #  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
  #  THE SOFTWARE.
  #
  
  """Null sequence IO. Acts like /dev/null. Read returns empty sequences or sequence lists, writes do nothing."""
  from __future__ import absolute_import
  
  from ..seq import Seq, SeqList
  
  names = ()
  extensions = ()
  
  
  def read(fin, alphabet=None):
      assert fin is not None  # Do something with arguments to quiet pychecker
      if alphabet is not None:
          pass
      return SeqList([])
  
  
  def iterseq(fin, alphabet=None):
      assert fin is not None
      if alphabet is not None:
          pass
      yield Seq('')
      return
  
  
  def write(fout, seqs):
      assert fout is not None
      assert seqs is not None
      return
  
  
  def writeseq(fout, seq):
      assert fout is not None
      assert seq is not None
      return
  