code: def __get_conn(self, flag_force_new=False, filename=None):
          
          flag_open_new = flag_force_new or not self._conn_is_open()
  
          if flag_open_new:
              if filename is None:
                  filename = self.filename
              # funny that __get_conn() calls _get_conn() but that's it
              conn = self._get_conn(filename)
              self._conn = conn
          else:
              conn = self._conn
          return conn
docs: Returns connection to database. Tries to return existing connection, unless flag_force_new
  
          Args:
              flag_force_new:
              filename:
  
          Returns: sqlite3.Connection object
  
          **Note** this is a private method because you can get a connection to any file, so it has to
                   be used in the right moment