coverity#704968 Unchecked dynamic_cast
coverity#704968 Unchecked dynamic_cast

Change-Id: Ifa12e220208d9a67213d1a58ab7e2b67083e2968

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core