Since HTTP requests frequently happen in parallel, connection pooling must be thread-safe.

These are the primary classes involved with establishing, sharing, and terminating connections:

<img src="/img/tutorial/body/image02.png">

## Editor support { #editor-support }

In your editor, inside your function you will get type hints and completion everywhere (this wouldn't happen if you received a `dict` instead of a Pydantic model):

<img src="/img/tutorial/body/image03.png">

You also get error checks for incorrect type operations:

<img src="/img/tutorial/body/image04.png">

        // Then - nothing should happen (empty implementation)
        verifyNoInteractions(request);
    }

    @Test
    @DisplayName("Should setup response correctly")
    void testSetupResponse() {
        // Given
        Response resp = mock(Response.class);

        // When
        response.setupResponse(resp);

        // Then - nothing should happen (empty implementation)

    for (int i = 0; i < 2; i++) {
      try {
        memoizedSupplier.get();
        fail("failed to throw NullPointerException");
      } catch (NullPointerException e) {
        // this is what should happen
      }
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testMemoizeNonSerializable() throws Exception {
    CountingSupplier countingSupplier = new CountingSupplier();

     */
    int FILE_READ_DATA = 0x00000001; // 1
    /**
     * Permission to write data to the file.
     */
    int FILE_WRITE_DATA = 0x00000002; // 2
    /**
     * Permission to append data to the file.
     */
    int FILE_APPEND_DATA = 0x00000004; // 3
    /**
     * Permission to read extended attributes.
     */
    int FILE_READ_EA = 0x00000008; // 4
    /**

            }
        }

        @Override
        public void characters(final char[] ch, final int offset, final int length) {
            if (buf != null) {
                buf.append(new String(ch, offset, length));
            }
        }

        @Override
        public void endElement(final String uri, final String localName, final String qName) {
            if (URL_ELEMENT.equals(qName)) {

                fbuf.reset();
                msg.decode_header(fbuf);
                stub_frag_len = msg.length - 24;

                if (off + stub_frag_len > stub.length) {
                    // shouldn't happen if alloc_hint is correct or greater
                    final byte[] tmp = new byte[off + stub_frag_len];
                    System.arraycopy(stub, 0, tmp, 0, off);
                    stub = tmp;
                }

                atTotal += pool.Available
                if atTotal > choose && pool.Available > 0 {
                        return pool.Index
                }
        }
        // Should not happen, but print values just in case.
        panic(fmt.Errorf("reached end of serverPools (total: %v, atTotal: %v, choose: %v)", total, atTotal, choose))
}
```

## Other usages

		EnvVar: "MINIO_ADDRESS",
	},
}

var fmtGenCmd = cli.Command{
	Name:   "fmt-gen",
	Usage:  "Generate format.json files for an erasure server pool",
	Flags:  append(fmtGenFlags, GlobalFlags...),
	Action: fmtGenMain,
	Hidden: true,
	CustomHelpTemplate: `NAME:
  {{.HelpName}} - {{.Usage}}

USAGE:
  {{.HelpName}} {{if .VisibleFlags}}[FLAGS] {{end}}DIR1 [DIR2..]

							return err
						}
						continue
					}
				}

				// NOT an object, append to stack (with slash)
				// If dirObject, but no metadata (which is unexpected) we skip it.
				if !isDirObj {
					if !isDirEmpty(pathJoinBuf(sb, volumeDir, meta.name), legacyFS) {
						dirStack = append(dirStack, meta.name+slashSeparator)
					}
				}
			case isSysErrNotDir(err):
				// skip
			}
		}