{* ../../docs_src/pydantic_v1_in_v2/tutorial004_an_py310.py hl[4,18] *}

### Migrate in steps { #migrate-in-steps }

/// tip

First try with `bump-pydantic`, if your tests pass and that works, then you're done in one command. ✨

///

    writer.println("rud a chur ar an méar fhada");
    writer.close();

    // First check that we can't find it without setting the context loader.
    // This is a sanity check that the test doesn't spuriously pass because
    // the resource is visible to the system class loader.
    assertThrows(IllegalArgumentException.class, () -> Resources.getResource(tempFile.getName()));

        if (uncaughtExceptionHandler != null) {
          thread.setUncaughtExceptionHandler(uncaughtExceptionHandler);
        }
        return thread;
      }
    };
  }

  // weird case in which users pass the format string but not the associated arguments
  @SuppressWarnings("AnnotateFormatMethod")
  private static String format(String format, Object... args) {
    return String.format(Locale.ROOT, format, args);
  }

* Ей не нужен реальный код, потому что ваше приложение никогда не будет вызывать эту функцию. Она используется только для документирования *внешнего API*. Поэтому в функции может быть просто `pass`.

    @Test
    public void test_security_pathTraversalWithLogExtension() {
        // These patterns attempt to access files outside the log directory
        // but must end with .log to pass isLogFilename check

        String sanitized1 = AdminLogAction.sanitizeFilename("../../../var/log/auth.log");
        assertEquals("/var/log/auth.log", sanitized1);

/// note | Technical Details

The other two variables, `image_base64` and `binary_image`, are an image encoded in Base64, and then converted to bytes, to then pass it to `io.BytesIO`.

Only so that it can live in the same file for this example and you can copy it and run it as is. 🥚

///

      }
    }
  }

  /**
   * Class used to test whether equals() correctly handles an instance of an incompatible class.
   * Since it is a private inner class, the invoker can never pass in an instance to the tester
   */
  private enum NotAnInstance {
    EQUAL_TO_NOTHING;
  }

        }
    }

    private static List<String> filesFromMerge(String commit) throws IOException, InterruptedException, ExecutionException {
        // Git revision range syntax is part of git, not the shell; pass as-is.
        return getStdoutLines(new String[] {"git", "diff", "--name-only", commit + "^1.." + commit});
    }

Then, in **FastAPI**, you could use a Python class as a dependency.

What FastAPI actually checks is that it is a "callable" (function, class or anything else) and the parameters defined.

If you pass a "callable" as a dependency in **FastAPI**, it will analyze the parameters for that "callable", and process them in the same way as the parameters for a *path operation function*. Including sub-dependencies.

		_, err = erasure.Decode(t.Context(), writer, bitrotReaders, test.offset, test.length, test.data, nil)
		closeBitrotReaders(bitrotReaders)
		if err != nil && !test.shouldFail {
			t.Errorf("Test %d: should pass but failed with: %v", i, err)
		}
		if err == nil && test.shouldFail {
			t.Errorf("Test %d: should fail but it passed", i)
		}
		if err == nil {