Function validate_key_holder 

pub fn validate_key_holder(
    ast: &Ast,
    request: &ProbeRequest,
) -> Result<(), ProbeError>

Validate the currently supported inverse holder shape without reading data.

Primitive, string, enumeration, alias and nested-structure keys are supported. Optional/external, collection and union key contexts are explicitly refused.

Errors

Unsupported holder shape or invalid layout.