old_contents: ##
  # Copyright (c) 2010 Sprymix Inc.
  # All rights reserved.
  #
  # See LICENSE for details.
  ##
  
  
  from semantix import SemantixError
  
  
  class UnsatisfiedRequirementError(SemantixError):
      pass
  
  
  class CommandRequirement:
      pass
  
new_contents: ##
  # Copyright (c) 2010 Sprymix Inc.
  # All rights reserved.
  #
  # See LICENSE for details.
  ##
  
  
  from semantix import app, SemantixError
  
  
  class UnsatisfiedRequirementError(SemantixError):
      pass
  
  
  class CommandRequirement:
      pass
  
  
  class ValidApplication(CommandRequirement):
      def __init__(self):
          if not app.Application.active:
              raise UnsatisfiedRequirementError('need active Application')
  
subject: Introduce Application class