new_contents: """
  BenchExec is a framework for reliable benchmarking.
  This file is part of BenchExec.
  
  Copyright (C) 2007-2015  Dirk Beyer
  All rights reserved.
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
  """
  
  # prepare for Python 3
  from __future__ import absolute_import, division, print_function, unicode_literals
  
  import subprocess
  
  import benchexec.util as util
  import benchexec.tools.smtlib2
  
  class Tool(benchexec.tools.smtlib2.Smtlib2Tool):
      """
      Tool info for z3.
      """
  
      def executable(self):
          return util.find_executable('z3')
  
      def version(self, executable):
          out = subprocess.Popen(self.cmdline(executable, ['-version'], []),
                                    stderr=subprocess.PIPE).communicate()[1]
          out = util.decode_to_string(out)
          return out.strip()
  
      def name(self):
          return 'z3'
  
      def cmdline(self, executable, options, tasks, propertyfile=None, rlimits={}):
          assert len(tasks) <= 1, "only one inputfile supported"
          return [executable] + options + tasks
  
subject: add z3 as supported tool