@NotNull
  private Stream<? extends IProperty> propertiesByKey(@NotNull String key) {
    if (shouldReadIndex()) {
      return PropertyKeyIndex.getInstance().getProperties(key, getProject(), GlobalSearchScope.fileScope(this)).stream();
    }
    // see PropertiesElementFactory.createPropertiesFile(Project, Properties, String)
    return getProperties().stream().filter(p -> key.equals(p.getUnescapedKey()));
  }
@NotNull
  private Stream<? extends IProperty> propertiesByKey(@NotNull String key)