It is just a function that can take all the same parameters that a *path operation function* can take:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[8:9] *}

That's it.

**2 lines**.

And it has the same shape and structure that all your *path operation functions* have.

You can think of it as a *path operation function* without the "decorator" (without the `@app.get("/some-path")`).

And it can return anything you want.

        
        while (!rdmaConnection.canSend() && System.currentTimeMillis() < deadline) {
            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                throw new IOException("Interrupted waiting for send credit", e);
            }
        }
        

    } catch (AssertionError expected) {
      return;
    }
    fail();
  }

  public void testNullsOnReturnValues_returnTypeFiltered() throws Exception {
    try {
      tester
          .forAllPublicStaticMethods(BadNullsFactory.class)
          .thatReturn(Iterable.class)
          .testNulls();
    } catch (AssertionError expected) {
      assertThat(expected)

        if (path.length() > MAX_PATH_SIZE) {
            failedValidations.incrementAndGet();
            log.warn("Path exceeds maximum length: {}", path.length());
            throw new SmbException("Path exceeds maximum length");
        }

        // Check for directory traversal
        if (path.contains("..") || path.contains("./") || path.contains(".\\")) {
            failedValidations.incrementAndGet();

            } catch (final Exception e) {
                if (logger.isDebugEnabled()) {
                    logger.debug("Failed to set a property.", e);
                }
            }
        }
        try {
            factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
        } catch (final ParserConfigurationException e) {

                        successCount.incrementAndGet();

                        // Small delay to increase chance of race conditions
                        Thread.yield();
                    }
                } catch (Exception e) {
                    exceptions.add(e);
                } finally {
                    endLatch.countDown();
                }
            });
        }

        // Start all threads simultaneously

            factory.setFeature("http://xml.org/sax/features/external-parameter-entities", false);
        } catch (SAXNotRecognizedException | SAXNotSupportedException e) {
            throw new SAXRuntimeException(e);
        } catch (final ParserConfigurationException e) {
            throw new ParserConfigurationRuntimeException(e);
        }
        return factory;
    }

    /**

      getMap().replace(k0(), v3(), v4());
    } catch (UnsupportedOperationException tolerated) {
      // the operation would be a no-op, so exceptions are allowed but not required
    }
    expectUnchanged();
  }

  @MapFeature.Require(absent = SUPPORTS_PUT)
  public void testReplaceEntry_unsupportedAbsentKey() {
    try {
      getMap().replace(k3(), v3(), v4());
    } catch (UnsupportedOperationException tolerated) {

ARGS:
endpoints*       (csv)       comma separated list of etcd endpoints e.g. "http://localhost:2379"
path_prefix      (path)      namespace prefix to isolate tenants e.g. "customer1/"
coredns_path     (path)      shared bucket DNS records, default is "/skydns"
client_cert      (path)      client cert for mTLS authentication
client_cert_key  (path)      client cert key for mTLS authentication
comment          (sentence)  optionally add a comment to this setting

## متغیر محیطی `PATH`

یه متغیر محیطی **خاص** به اسم **`PATH`** وجود داره که سیستم‌عامل‌ها (لینوکس، مک‌اواس، ویندوز) ازش برای پیدا کردن برنامه‌هایی که قراره اجرا بشن استفاده می‌کنن.

مقدار متغیر `PATH` یه رشته طولانی از پوشه‌هاست که توی لینوکس و مک‌اواس با دونقطه `:` و توی ویندوز با نقطه‌ویرگول `;` از هم جدا شدن.

مثلاً، متغیر محیطی `PATH` می‌تونه اینجوری باشه:

//// tab | لینوکس، مک‌اواس