old_contents: #!/usr/bin/env python2.7
  
  class OAError(Exception):
      """Exception for general purpose openarc error"""
      def __init__(self, message):
          super(OAError, self).__init__(message)
          self.message = message
  
  class OAGraphRetrieveError(Exception):
      """Raised when data retrieval fails"""
      def __init__(self, message):
          super(OAGraphRetrieveError, self).__init__(message)
          self.message = message
  
  class OAGraphIntegrityError(Exception):
      """Raised when data integrity issues are detected"""
      def __init__(self, message):
          super(OAGraphIntegrityError, self).__init__(message)
          self.message = message
  
  class OAMarketError(Exception):
      """Exception throw upon incorrect interaction with a market"""
      def __init__(self, message):
          super(OAMarketError, self).__init__(message)
          self.message = message
  
new_contents: #!/usr/bin/env python2.7
  
  class OAError(Exception):
      """Exception for general purpose openarc error"""
      def __init__(self, message):
          super(OAError, self).__init__(message)
          self.message = message
  
  class OAGraphRetrieveError(Exception):
      """Raised when data retrieval fails"""
      def __init__(self, message):
          super(OAGraphRetrieveError, self).__init__(message)
          self.message = message
  
  class OAGraphIntegrityError(Exception):
      """Raised when data integrity issues are detected"""
      def __init__(self, message):
          super(OAGraphIntegrityError, self).__init__(message)
          self.message = message
  
subject: Move market-specific exception to proprietary library