whenOrNull<TResult extends Object?> method Null safety

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  1. {TResult? initialized(
      )?,
    1. TResult? joining(
        )?,
      1. TResult? joined(
        1. CallConfig callConfig
        )?,
      2. TResult? leaving(
          )?,
        1. TResult? left(
            )?}
          )
          inherited

          Implementation

          @optionalTypeArgs
          TResult? whenOrNull<TResult extends Object?>({
            TResult? Function()? initialized,
            TResult? Function()? joining,
            TResult? Function(
                    @JsonKey(name: 'callConfiguration') CallConfig callConfig)?
                joined,
            TResult? Function()? leaving,
            TResult? Function()? left,
          }) =>
              throw _privateConstructorUsedError;