@Nullable
  private PsiElement resolveToCustomSystemProperty(@NotNull String propertyName, @Nullable String propertyValue) {
    if (propertyValue == null) return null;

    PsiFile propFile = PsiFileFactory.getInstance(myProject).createFileFromText("SystemProperties.properties", PropertiesLanguage.INSTANCE,
                                                                                propertyName + '=' + propertyValue);

    return ((PropertiesFile)propFile).getProperties().get(0).getPsiElement();
  }
@Nullable
  private PsiElement resolveToCustomSystemProperty(@NotNull String propertyName, @Nullable String propertyValue)