tests/cases/conformance/es6/Symbols/symbolProperty35.ts(8,11): error TS2320: Interface 'I3' cannot simultaneously extend types 'I1' and 'I2'.
  Named property '[Symbol.toStringTag]' of types 'I1' and 'I2' are not identical.


==== tests/cases/conformance/es6/Symbols/symbolProperty35.ts (1 errors) ====
    interface I1 {
        [Symbol.toStringTag](): { x: string }
    }
    interface I2 {
        [Symbol.toStringTag](): { x: number }
    }
    
    interface I3 extends I1, I2 { }
              ~~
!!! error TS2320: Interface 'I3' cannot simultaneously extend types 'I1' and 'I2'.
!!! error TS2320:   Named property '[Symbol.toStringTag]' of types 'I1' and 'I2' are not identical.