Why is there no options to set node and edge nonnull on connection field?

I've been trying to set nonnull to node and edge on connection field
because a frontend engineer told me that he've got a lot of things to handler if node and edge are nullable.
is there a specific reason node and edge set to nullable?

未指定檔案或測試。首先定位 connection-field 的實作，並檢查 node 和 edge 的 nullability 是如何定義的，然後將要求的選項與目前 GraphQL schema 的行為進行比較。在找到進入點後確認測試，並取得 maintainer 核准的說明或範圍明確的實作決策，即視為完成。

由索引模型根據 Issue 內容生成。