from Query Field
Path to a field in the Query root's selection set.
The path must exist in the queryValueFragment.
Example: "currentUser.id"
Return
the query field path, or empty string if not using this source
Path to a field in the Query root's selection set.
The path must exist in the queryValueFragment.
Example: "currentUser.id"
the query field path, or empty string if not using this source