old_contents: #!/usr/bin/env python
  from __future__ import print_function
  
  import logging
  
  logger = logging.getLogger(__name__)
  
  
  def install(pkgs, verbose):
      pass
  
  
  def update(verbose):
      pass
  
  
  def remove(pkgs, verbose):
      pass
  
  
  def upgrade(verbose):
      pass
  
new_contents: #!/usr/bin/env python
  from __future__ import print_function
  
  import logging
  import os
  
  from .utils import mkdir_p
  from .workspace import ws_file
  
  logger = logging.getLogger(__name__)
  installed_dir = os.path.join(ws_file, '.env', 'installed')
  target_path = os.path.join(ws_file, 'src')
  
  
  def install(pkgs, verbose):
      pkgs_queue = list(pkgs)
      print('TODO: %s' % pkgs)
  
  
  def update(verbose):
      pass
  
  
  def remove(pkgs, verbose):
      pass
  
  
  def upgrade(verbose):
      pass
  
  
  def add_pkgs_to_installed_list(pkgs):
      mkdir_p(installed_dir)
  
      # touch the file
      for pkg in pkgs:
          logger.debug('marking for installation: %s', pkg)
          open(os.path.join(installed_dir, pkg), 'a').close()
  
subject: Determine dirs