code: def _make_field_doc(name, ftype, subfield):
      if ftype == "fiftyone.core.fields.ObjectIdField":
          db_field = "_" + name
      else:
          db_field = name
  
      return {
          "_cls": "SampleFieldDocument",
          "name": name,
          "ftype": ftype,
          "subfield": subfield,
          "embedded_doc_type": None,
          "db_field": db_field,
          "fields": [],
      }
  
label_desc: Use image node_id 5 for calling a global function with example usage: _make_field_doc(name, ftype, subfield) and returns: dict