code: func NewSessionVars() *SessionVars {
  	return &SessionVars{
  		Users:         make(map[string]string),
  		Systems:       make(map[string]string),
  		TxnCtx:        &TransactionContext{},
  		StrictSQLMode: true,
  		Status:        mysql.ServerStatusAutocommit,
  		StmtCtx:       new(StatementContext),
  	}
  }
docs: // NewSessionVars creates a session vars object.