==== tests/cases/compiler/duplicateInterfaceMembers1.ts (1 errors) ====
    interface Bar {
       x: number;
       x: number;
       ~
!!! duplicateInterfaceMembers1.ts(3,4): error TS2000: Duplicate identifier 'x'. Additional locations:
!!! 	duplicateInterfaceMembers1.ts(2,4)
    }
    