docs: def conn_is_open(conn):
      """Tests sqlite3 connection, returns T/F"""
      if conn is None:
          return False
  
      try:
          get_table_names(conn)
          return True
  
          # # Idea taken from
          # # http: // stackoverflow.com / questions / 1981392 / how - to - tell - if -python - sqlite - database - connection - or -cursor - is -closed
          # conn.execute("select id from molecule limit 1")
          # return True
      except sqlite3.ProgrammingError as e:
          # print(e)
          return False