Function get_blob_field 

pub fn get_blob_field<const N: usize, const CODE: i32>(
    _: SField<Blob<N>, CODE>,
) -> Result<Blob<N>>

Retrieves a Blob<N> field from the current transaction, writing the host’s bytes directly into the returned Blob<N>’s own storage. See the module comment block above for why Blob<N> gets a dedicated accessor instead of using get_field.