buffer.write(upstreamBuffer, upstreamBytesRead)
          if (buffer.size > bufferMaxSize) {
            buffer.skip(buffer.size - bufferMaxSize)
          }

          // Now that the file and buffer have bytes, adjust upstreamPos.
          ******@****.***amPos += upstreamBytesRead
        }

        return bytesRead
      } finally {
        synchronized(this@Relay) {

                setStatus(qr, NtStatus.NT_STATUS_NO_SUCH_FILE);
                qr.received();
                q.setResponse(qr);
                // Now emulate error thrown by transport for create chain
                throw new SmbException(NtStatus.NT_STATUS_NO_SUCH_FILE, false);
            }
            return null;
        }).when(tree).send(any(Request.class));

        verify(tree, never()).send(any(CommonServerMessageBlockRequest.class), any(SmbComBlankResponse.class), any(RequestParam[].class));

        // Second release: should close now via SMB2 path
        h.release();
        verify(tree, times(1)).send(isA(Smb2CloseRequest.class), eq(RequestParam.NO_RETRY));
        verify(tree, times(1)).release();
    }

    @Test

          setFuture((ListenableFuture<O>) localInputFuture); // Respects cancellation cause setting
      return;
    }

    /*
     * Any of the setException() calls below can fail if the output Future is cancelled between now
     * and then. This means that we're silently swallowing an exception -- maybe even an Error. But
     * this is no worse than what FutureTask does in that situation. Additionally, because the

		if sync := test.rcfg.resync(test.info, test.dsc, test.tgtStatuses); sync.mustResync() != test.expectedSync {
			t.Errorf("%s (%s): Replicationresync  got %t , want %t", fmt.Sprintf("Test%d - %s", i+1, time.Now().Format(http.TimeFormat)), test.name, sync.mustResync(), test.expectedSync)
		}
	}

		j--
	}

	if j > 1 {
		// Create parent.
		if err := osMkdirAll(dirPath[:j-1], perm, baseDir); err != nil {
			return err
		}
	}

	// Parent now exists; invoke Mkdir and use its result.
	if err := Mkdir(dirPath, perm); err != nil {
		if osIsExist(err) {
			return nil
		}
		return err
	}

	return nil
}

     */
    public void storeSearchLog() {
        final SearchLogBhv searchLogBhv = ComponentUtil.getComponent(SearchLogBhv.class);

        searchLogBhv.selectBulk(cb -> {
            final String from = LocalDateTime.now().minusDays(fessConfig.getPurgeSuggestSearchLogDay()).format(DateTimeFormatter.ISO_DATE);
            cb.query().addQuery(QueryBuilders.rangeQuery("requestedAt").gte(from));
            cb.query().addOrderBy_RequestedAt_Asc();

        // Then: Should use trans1 (addr2 failed, so tried addr1 next)
        assertSame(trans1, result);

        // Verify fail count incremented for addr2 (was 1, now 2)
        assertEquals(2, poolSpy.failCounts.get("10.0.0.2"));
        // addr1's count should remain unchanged since it succeeded
        assertEquals(5, poolSpy.failCounts.get("10.0.0.1"));
    }

    @Test

      .containsExactlyInAnyOrder(a1, a2)
    assertThat(dispatcher.queuedCalls()).isEmpty()

    // Let the calls finish.
    waiting.countDown()
    t1.join()
    t2.join()

    // Now we should have 0 running calls and 0 queued calls.
    assertThat(dispatcher.runningCallsCount()).isEqualTo(0)
    assertThat(dispatcher.queuedCallsCount()).isEqualTo(0)
    assertThat(dispatcher.runningCalls()).isEmpty()

* And many other things...

All these, while minimizing code repetition.

## First Steps { #first-steps }

Let's see a very simple example. It will be so simple that it is not very useful, for now.

But this way we can focus on how the **Dependency Injection** system works.

### Create a dependency, or "dependable" { #create-a-dependency-or-dependable }

Let's first focus on the dependency.