assertTrue(str.contains("count="), "Should contain count");
        assertTrue(str.contains("offset="), "Should contain offset");
    }

  }

  @Override
  protected void expectMissing(Entry<K, V>... entries) {
    for (Entry<K, V> entry : entries) {
      assertFalse("Should not contain entry " + entry, actualContents().contains(entry));
      assertFalse(
          "Should not contain key " + entry.getKey() + " mapped to value " + entry.getValue(),
          equal(getMap().get(entry.getKey()), entry.getValue()));
    }
  }

        assertTrue(infoString.contains("alloc=1000"), "toString should contain alloc");
        assertTrue(infoString.contains("free=500"), "toString should contain free");
        assertTrue(infoString.contains("sectPerAlloc=100"), "toString should contain sectPerAlloc");
        assertTrue(infoString.contains("bytesPerSect=512"), "toString should contain bytesPerSect");
    }

      BiMap<V, K> inv = getMap().inverse();
      assertFalse(
          "Inverse should not contain entry " + reversed, inv.entrySet().contains(reversed));
      assertFalse(
          "Inverse should not contain key " + reversed.getKey(),
          inv.containsKey(reversed.getKey()));
      assertFalse(
          "Inverse should not contain value " + reversed.getValue(),
          inv.containsValue(reversed.getValue()));
      /*

        assertTrue(resultString.contains("status=0"), "toString should contain the status.");
        assertTrue(resultString.contains("converter=13330"), "toString should contain the converter.");
        assertTrue(resultString.contains("entriesReturned=2"), "toString should contain the number of entries.");
        assertTrue(resultString.contains("totalAvailableEntries=5"), "toString should contain the total available entries.");
    }

        String s = session.toString();
        assertTrue(s.contains("accountName="), "toString should contain accountName");
        assertTrue(s.contains("primaryDomain="), "toString should contain primaryDomain");
        assertTrue(s.contains("uid="), "toString should contain uid");
    }

        #        ; tableExceptList=list:{FOO_TABLE ; prefix:FOO_ ; suffix:_FOO ; contain:_FOO_}
        #        ; tableTargetList=list:{FOO_TABLE ; prefix:FOO_ ; suffix:_FOO ; contain:_FOO_}
        #        ; columnExceptMap=map:{
        #            ; FOO_TABLE = list:{FOO_COLUMN ; prefix:FOO_ ; suffix:_FOO ; contain:_FOO_}
        #        }
        #        ; isSuppressCommonColumn=false

        String ts = ex.toString();
        assertTrue(ts.contains("SmbUnsupportedOperationException"), "toString should contain class name");
        if (msg != null) {
            assertTrue(ts.contains(msg), "toString should contain provided message");
        } else {
            assertFalse(ts.contains(":"), "toString should not contain ':' when message is null");
        }
    }

    @Test

Let's first see how the normal API app would look like before adding the callback.

It will have a *path operation* that will receive an `Invoice` body, and a query parameter `callback_url` that will contain the URL for the callback.

This part is pretty normal, most of the code is probably already familiar to you:

{* ../../docs_src/openapi_callbacks/tutorial001.py hl[9:13,36:53] *}

/// tip

        // toString uses Hexdump.toHexString(informationLevel, 3)
        assertTrue(str.contains(Hexdump.toHexString(level, 3)), "toString should contain hex level");
        assertTrue(str.contains("Trans2QueryFSInformation["), "should start with class name");
        assertTrue(str.contains(",informationLevel=0x"), "should contain level field marker");
    }