/** Adds the chain to the seen set, and returns whether all the chain was new to us. */
  private static boolean addCausalChain(Set<Throwable> seen, Throwable param) {
    // Declare a "true" local variable so that the Checker Framework will infer nullness.
    Throwable t = param;

    for (; t != null; t = t.getCause()) {
      boolean firstTimeSeen = seen.add(t);
      if (!firstTimeSeen) {
        /*

       */

      //
      seenExceptionsLocal = newConcurrentHashSet();
      /*
       * Other handleException() callers may see this as soon as we publish it. We need to populate
       * it with the initial failure before we do, or else they may think that the initial failure
       * has never been seen before.
       */
      addInitialException(seenExceptionsLocal);

| `minio_node_replication_max_queued_count`               | Maximum number of objects queued for replication seen since server start                                 |
| `minio_node_replication_recent_backlog_count`           | Total number of objects seen in replication backlog in the last 5 minutes                                |

        new LineProcessor<Integer>() {
          int seen;

          @Override
          public boolean processLine(String line) {
            seen++;
            sb.append(line);
            return seen < 2;
          }

          @Override
          public Integer getResult() {
            return seen;
          }
        };

        new LineProcessor<Integer>() {
          int seen;

          @Override
          public boolean processLine(String line) {
            seen++;
            sb.append(line);
            return seen < 2;
          }

          @Override
          public Integer getResult() {
            return seen;
          }
        };

        // we want to see all top-level thread groups
        ThreadGroup tg = Thread.currentThread().getThreadGroup();
        while (tg.getParent() == null) {
            tg = tg.getParent();
        }

        ThreadGroup[] tgList = new ThreadGroup[tg.activeGroupCount()];
        tg.enumerate(tgList);

        boolean seen = false;

        for (ThreadGroup aTgList : tgList) {

     */
    private int countUniqueBytes(byte[] data) {
        boolean[] seen = new boolean[256];
        int count = 0;

        for (byte b : data) {
            int index = b & 0xFF;
            if (!seen[index]) {
                seen[index] = true;
                count++;
            }
        }

        return count;
    }

# Advanced Dependencies { #advanced-dependencies }

## Parameterized dependencies { #parameterized-dependencies }

All the dependencies we have seen are a fixed function or class.

But there could be cases where you want to be able to set parameters on the dependency, without having to declare many different functions or classes.

Let's imagine that we want to have a dependency that checks if the query parameter `q` contains some fixed content.

    void codes_are_non_negative_and_unique() {
        // Edge checks: ensure there are no negative or duplicate codes
        Set<Integer> seen = new HashSet<>();
        for (int c : WinError.WINERR_CODES) {
            assertTrue(c >= 0, "Code should be non-negative: " + c);
            assertTrue(seen.add(c), "Duplicate code detected: " + c);
        }
    }

    // Simple collaborator to demonstrate interaction verification with Mockito

* `ge`: `g`reater than or `e`qual
* `lt`: `l`ess `t`han
* `le`: `l`ess than or `e`qual

/// info

`Query`, `Path`, and other classes you will see later are subclasses of a common `Param` class.

All of them share the same parameters for additional validation and metadata you have seen.

///

/// note | Technical Details

When you import `Query`, `Path` and others from `fastapi`, they are actually functions.