@Nullable
  @Override
  public ConversionResult isConvertible(@NotNull PsiType targetType,
                                        @NotNull PsiType actualType,
                                        @NotNull Position position,
                                        @NotNull GroovyPsiElement context) {
    if (!isEnum(targetType)) return null;
    if (InheritanceUtil.isInheritor(actualType, GroovyCommonClassNames.GROOVY_LANG_GSTRING) ||
        InheritanceUtil.isInheritor(actualType, CommonClassNames.JAVA_LANG_STRING)) {
      return GroovyConfigUtils.getInstance().isVersionAtLeast(context, GroovyConfigUtils.GROOVY1_8)
             ? ConversionResult.OK
             : ConversionResult.ERROR;
    }
    return null;
  }
@Nullable
  @Override
  public ConversionResult isConvertible(@NotNull PsiType targetType,
                                        @NotNull PsiType actualType,
                                        @NotNull Position position,
                                        @NotNull GroovyPsiElement context)