old_contents: # Copyright (c) 2009-2021 The Regents of the University of Michigan
  # This file is part of the HOOMD-blue project, released under the BSD 3-Clause
  # License.
  
  """HOOMD Errors."""
  
  
  class DataAccessError(RuntimeError):
      """Raised when data is inaccessible until the simulation is run."""
  
      def __init__(self, data_name):
          self.data_name = data_name
  
      def __str__(self):
          """Returns the error message."""
          return (f'The property {self.data_name} is unavailable until the '
                  'simulation runs for 0 or more steps.')
  
  
  class TypeConversionError(ValueError):
      """Error when validatimg TypeConverter subclasses fails."""
      pass
  
new_contents: # Copyright (c) 2009-2021 The Regents of the University of Michigan
  # This file is part of the HOOMD-blue project, released under the BSD 3-Clause
  # License.
  
  """HOOMD Errors."""
  
  
  class DataAccessError(RuntimeError):
      """Raised when data is inaccessible until the simulation is run."""
  
      def __init__(self, data_name):
          self.data_name = data_name
  
      def __str__(self):
          """Returns the error message."""
          return (f'The property {self.data_name} is unavailable until the '
                  'simulation runs for 0 or more steps.')
  
  
  class TypeConversionError(ValueError):
      """Error when validatimg TypeConverter subclasses fails."""
      pass
  
  
  class SimulationDefinitionError(RuntimeError):
      """Error in definition of simulation internal state."""
      pass
  
subject: Add SimulationDefinitionError exception class