old_contents: """
  Simple Postgres health check.
  
  """
  from microcosm_postgres.context import SessionContext
  
  
  def check_health(graph):
      SessionContext.session.execute("SELECT 1;")
  
new_contents: """
  Simple Postgres health check.
  
  """
  from microcosm_postgres.context import SessionContext
  
  
  def check_health(graph):
      """
      Basic database health check.
  
      """
      SessionContext.session.execute("SELECT 1;")
  
  
  def check_alembic(graph):
      """
      Check connectivity to an alembic database.
  
      Returns the current migration.
  
      """
      return SessionContext.session.execute(
          "SELECT version_num FROM alembic_version LIMIT 1;",
      ).scalar()
  
subject: Add an alembic health check