def _migrate_states_schema(versioned_exploration_states):
 states_schema_version = versioned_exploration_states['states_schema_version']
 if ((states_schema_version is None) or (states_schema_version < 1)):
  states_schema_version = 0
 if (not (0 <= states_schema_version <= feconf.CURRENT_EXPLORATION_STATES_SCHEMA_VERSION)):
  raise Exception(('Sorry, we can only process v1-v%d and unversioned exploration state schemas at present.' % feconf.CURRENT_EXPLORATION_STATES_SCHEMA_VERSION))
 while (states_schema_version < feconf.CURRENT_EXPLORATION_STATES_SCHEMA_VERSION):
  exp_domain.Exploration.update_states_from_model(versioned_exploration_states, states_schema_version)
  states_schema_version += 1

def _migrate_states_schema ( versioned_exploration_states ) : states_schema_version = versioned_exploration_states [ 'states_schema_version' ] if ( ( states_schema_version is None ) or ( states_schema_version < 1 ) ) : states_schema_version = 0 if ( not ( 0 <= states_schema_version <= feconf . CURRENT_EXPLORATION_STATES_SCHEMA_VERSION ) ) : raise Exception ( ( 'Sorry, we can only process v1-v%d and unversioned exploration state schemas at present.' % feconf . CURRENT_EXPLORATION_STATES_SCHEMA_VERSION ) ) while ( states_schema_version < feconf . CURRENT_EXPLORATION_STATES_SCHEMA_VERSION ) : exp_domain . Exploration . update_states_from_model ( versioned_exploration_states , states_schema_version ) states_schema_version += 1
holds the responsibility of performing a step-by-step .