new_contents: #!/usr/bin/env python3
  # Copyright (c) 2015 Matthew Earl
  # 
  # 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.
  
  """
  A simple example, placing 4 resistors in a loop on a 2x4 strip board.
  
  Three of the resistors have a maximum length of 1, whereas the other has a
  maximum length of 3. There should be 4 solutions in total.
  
  """
  
  import component
  import placer
  
  r1 = component.LeadedComponent(3)
  r2 = component.LeadedComponent(1)
  r3 = component.LeadedComponent(1)
  r4 = component.LeadedComponent(1)
  
  board = component.StripBoard((2, 4))
  
  nets = (
      (r1.terminals[1], r2.terminals[0]),
      (r2.terminals[1], r3.terminals[0]),
      (r3.terminals[1], r4.terminals[0]),
      (r4.terminals[1], r1.terminals[0]),
  )
  
  for placement in placer.place(board, (r1, r2, r3, r4), nets):
      print("R1: {}".format(placement[r1]))
      print("R2: {}".format(placement[r2]))
      print("R3: {}".format(placement[r3]))
      print("R4: {}".format(placement[r4]))
      print()
  
  
subject: Add a 4 resistors example