code: func (s *SessionVars) RemovePreparedStmt(stmtID uint32) {
  	_, exists := s.PreparedStmts[stmtID]
  	if !exists {
  		return
  	}
  	delete(s.PreparedStmts, stmtID)
  	afterMinus := atomic.AddInt64(&preparedStmtCount, -1)
  	metrics.PreparedStmtGauge.Set(float64(afterMinus))
  }
docs: // RemovePreparedStmt removes preparedStmt from current session and decrease count in global.