MALFORMED_FILE_REF error condition
FileType value is malformed.
MISSING_URI_KEY
The dict is missing the required 'uri' key.
URI_NOT_STRING
The 'uri' field must be a string, but got <actualType>.
URI_NULL
The 'uri' field must not be null.
WRONG_ARITY
Expected <expected> fields, but got <actual>.
WRONG_TYPE
Expected <expected>, but got <actualType>.