question: adding optional field is compatible concode_field_sep PlaceHolder placeHolder concode_field_sep ThriftType.StructType struct concode_elem_sep void testList concode_elem_sep void testRenameField concode_elem_sep void testRemoveOptionalField concode_elem_sep void testAddRequiredField concode_elem_sep void testReuirementChange concode_elem_sep void testSet concode_elem_sep void testTypeChange concode_elem_sep void verifyCompatible concode_elem_sep void testMap
target: void function ( ) { verifyCompatible ( StructV1 . class , StructV2 . class , true ) ; }