old_contents: """
  Test case:
  
  plotpot
  plotpot -h
  plotpot -V
      
      
  """
  import sys
  from distutils.spawn import find_executable
  
  # check if prerequisites are installed
  try:
      from plotpot.__version__ import version
  except ImportError as error:
      print("Package not installed with pip.")
      sys.exit(error)
      
  try:
      import numpy as np
  except ImportError as error:
      print("Please install Python Numpy from http://numpy.scipy.org/")
      sys.exit(error)
      
  try:
      import matplotlib.pyplot as plt
  except ImportError as error:
      print("Please install Python Matplotlib from http://matplotlib.sourceforge.net/")
      sys.exit(error)
      
  convpot_program = find_executable("convpot")
  if not convpot_program:
      print("Please install Convpot from https://github.com/ahpohl/convpot/")
      sys.exit()
new_contents: import sys
  from distutils.spawn import find_executable
  
  # check if prerequisites are installed
  try:
      from plotpot.__version__ import version
  except ImportError as error:
      print("Package not installed with pip.")
      sys.exit(error)
      
  try:
      import numpy as np
  except ImportError as error:
      print("Please install Python Numpy from http://numpy.scipy.org/")
      sys.exit(error)
      
  try:
      import matplotlib.pyplot as plt
  except ImportError as error:
      print("Please install Python Matplotlib from http://matplotlib.sourceforge.net/")
      sys.exit(error)
      
  convpot_program = find_executable("convpot")
  if not convpot_program:
      print("Please install Convpot from https://github.com/ahpohl/convpot/")
      sys.exit()
subject: remove test case