code: func (h *StmtHistory) Add(stmtID uint32, st sqlexec.Statement, stmtCtx *stmtctx.StatementContext, params ...interface{}) {
  	s := &stmtRecord{
  		stmtID:  stmtID,
  		st:      st,
  		stmtCtx: stmtCtx,
  		params:  append(([]interface{})(nil), params...),
  	}
  	h.history = append(h.history, s)
  }
docs: // Add appends a stmt to history list.