@Nullable
    @Override
    TypeConversionDescriptor findCompoundAssignmentConversion(@NotNull PsiType from,
                                                              @NotNull PsiExpression expression,
                                                              @NotNull String sign,
                                                              @NotNull String binarySign) {
      final PsiPrimitiveType unboxedType = PsiPrimitiveType.getUnboxedType(from);
      final String valueType = (unboxedType != null ? unboxedType : from).getCanonicalText();
      return new TypeConversionDescriptor("$qualifier$ " + sign + " $val$",
                                          "$qualifier$.set((" + valueType + ")($qualifier$.get() " + binarySign + " ($val$)))",
                                          expression);
    }
@Nullable
    @Override
    TypeConversionDescriptor findCompoundAssignmentConversion(@NotNull PsiType from,
                                                              @NotNull PsiExpression expression,
                                                              @NotNull String sign,
                                                              @NotNull String binarySign)