Produced by fields.nullable(...) -- recognized only during buildData's schema-authoring walk; the resolved runtime default is always null.
fields.nullable(...)
buildData
null
Readonly
Internal marker discriminant -- see the module doc comment.
The declared inner default, kept only so the underlying type can be inferred -- never the resolved runtime value.
Produced by
fields.nullable(...)-- recognized only duringbuildData's schema-authoring walk; the resolved runtime default is alwaysnull.