private static void startStreamUnknown(@NotNull CFGBuilder builder,
                                         @NotNull Step firstStep,
                                         @NotNull PsiExpression originalQualifier,
                                         boolean originalQualifierAlreadyChecked,
                                         @Nullable PsiType inType) {
    if (!originalQualifierAlreadyChecked) {
      builder
        .pushExpression(originalQualifier)
        .chain(b -> checkAndMarkConsumed(b, originalQualifier))
        .pop();
    }
    builder
      .chain(firstStep::before)
      .pushUnknown()
      .ifConditionIs(true)
      .chain(b -> makeMainLoop(b, firstStep, inType))
      .end();
  }
private static void startStreamUnknown(@NotNull CFGBuilder builder,
                                         @NotNull Step firstStep,
                                         @NotNull PsiExpression originalQualifier,
                                         boolean originalQualifierAlreadyChecked,
                                         @Nullable PsiType inType)