new_contents: import sqlalchemy as sql
  from keystone.common import sql as ks_sql
  
  def upgrade(migrate_engine):
      meta = sql.MetaData()
      meta.bind = migrate_engine
  
      if migrate_engine.name == 'mysql':
          # In Folsom we explicitly converted migrate_version to UTF8.
          migrate_engine.execute(
              'ALTER TABLE migrate_version CONVERT TO CHARACTER SET utf8')
          # Set default DB charset to UTF8.
          migrate_engine.execute(
              'ALTER DATABASE %s DEFAULT CHARACTER SET utf8' %
              migrate_engine.url.database)
      
      trust = sql.Table(
          'trust', meta,
          sql.Column('id', sql.String(length=64), primary_key=True),
          sql.Column('trustor_user_id', sql.String(length=64), nullable=False),
          sql.Column('trustee_user_id', sql.String(length=64), nullable=False),
          sql.Column('project_id', sql.String(length=64)),
          sql.Column('impersonation', sql.Boolean, nullable=False),
          sql.Column('deleted_at', sql.DateTime),
          sql.Column('expires_at', sql.DateTime),
          sql.Column('remaining_uses', sql.Integer, nullable=True),
          sql.Column('extra', ks_sql.JsonBlob.impl),
          mysql_engine='InnoDB',
          mysql_charset='utf8')
  
      trust_role = sql.Table(
          'trust_role', meta,
          sql.Column('trust_id', sql.String(length=64), primary_key=True,
                     nullable=False),
          sql.Column('role_id', sql.String(length=64), primary_key=True,
                     nullable=False),
          mysql_engine='InnoDB',
          mysql_charset='utf8')
      
      trust.create()
      trust_role.create()
subject: add trust related tables back to DB.