@Nullable
  @Override
  public ConversionResult isConvertible(@NotNull PsiType lType,
                                        @NotNull PsiType rType,
                                        @NotNull Position position,
                                        @NotNull GroovyPsiElement context) {
    if (!isClassType(lType, JAVA_LANG_STRING)) return null;
    if (position == Position.EXPLICIT_CAST || position == Position.METHOD_PARAMETER) {
      return isClassType(rType, GROOVY_LANG_GSTRING)
             ? ConversionResult.OK
             : null;
    }
    return ConversionResult.OK;
  }
@Nullable
  @Override
  public ConversionResult isConvertible(@NotNull PsiType lType,
                                        @NotNull PsiType rType,
                                        @NotNull Position position,
                                        @NotNull GroovyPsiElement context)