old_contents: """
  """
  
  
  class ZazoError(Exception):
      """Base of all exceptions
      """
  
  
  class CannotSatisfy(ZazoError):
      """A requested candidate cannot be satisfied
      """
  
  
  class GraphError(ZazoError):
      """Base of all Graph related exceptions
      """
  
  
  class DuplicateVertexError(GraphError):
      """A vertex cannot be duplicated
      """
  
  
  class NonExistentVertexError(ZazoError):
      """A vertex does not exist in class
      """
  
new_contents: """
  """
  
  
  class ZazoError(Exception):
      """Base of all exceptions
      """
  
  
  class CannotSatisfy(ZazoError):
      """A requested candidate cannot be satisfied
      """
  
subject: Remove redundant exceptions