code: @Nullable
      public static InputStream getResourceAsStream(@NotNull String resource) {
          final ClassLoader classLoader = FileUtils.class.getClassLoader();
          final InputStream inputStream = classLoader != null
                  ? classLoader.getResourceAsStream(resource)
                  : ClassLoader.getSystemResourceAsStream(resource);
  
          if (inputStream == null) {
              try {
                  return new FileInputStream(resource);
              } catch (final FileNotFoundException e) {
                  LOGGER.error("Unable to create an Input Stream for " + resource, e);
              }
          }
          return inputStream;
      }
docs: Gets the {@link java.io.InputStream} for this resource.
  
  @param resource path
  @return the input stream for the given resource