```Python hl_lines="8  10"
{!> ../../docs_src/query_params/tutorial004.py!}
```

////

## Required query parameters

When you declare a default value for non-path parameters (for now, we have only seen query parameters), then it is not required.

If you don't want to add a specific value but just make it optional, set the default as `None`.

  tensorflow::string underlying_device;
  // Set to true whenever a TensorHandle is copied onto the device
  bool* arrived_flag;
  // Set to true whenever an operation is executed
  bool* executed_flag;
  // If true, only explicit op placements are accepted. If false, uses
  // type-based dispatch.
  bool strict_scope_placement;
};

struct LoggedTensor {
  TFE_TensorHandle* tensor;
  LoggedTensor() = delete;

  }

  /**
   * Returns an instance which specifies that ordering is guaranteed to be always be the same across
   * iterations, and across releases. Some methods may have stronger guarantees.
   *
   * <p>This instance is only useful in combination with {@code incidentEdgeOrder}, e.g. {@code
   * graphBuilder.incidentEdgeOrder(ElementOrder.stable())}.
   *
   * <h3>In combination with {@code incidentEdgeOrder}</h3>
   *

  }

  @Override
  public Set<E> edgesConnecting(N nodeU, N nodeV) {
    NetworkConnections<N, E> connectionsU = checkedConnections(nodeU);
    if (!allowsSelfLoops && nodeU == nodeV) { // just an optimization, only check reference equality
      return ImmutableSet.of();
    }
    checkArgument(containsNode(nodeV), NODE_NOT_IN_GRAPH, nodeV);
    return nodePairInvalidatableSet(connectionsU.edgesConnecting(nodeV), nodeU, nodeV);
  }

      public boolean remove(@CheckForNull Object o) {
        throw new UnsupportedOperationException();
      }

      // Mostly safe: We check contains(u) before calling successors(u), so we perform unsafe
      // operations only in weird cases like checking for an EndpointPair<ArrayList> in a
      // Graph<LinkedList>.
      @SuppressWarnings("unchecked")
      @Override
      public boolean contains(@CheckForNull Object obj) {

  }

  /**
   * Returns an instance which specifies that ordering is guaranteed to be always be the same across
   * iterations, and across releases. Some methods may have stronger guarantees.
   *
   * <p>This instance is only useful in combination with {@code incidentEdgeOrder}, e.g. {@code
   * graphBuilder.incidentEdgeOrder(ElementOrder.stable())}.
   *
   * <h3>In combination with {@code incidentEdgeOrder}</h3>
   *

  }

  @Override
  public Set<E> edgesConnecting(N nodeU, N nodeV) {
    NetworkConnections<N, E> connectionsU = checkedConnections(nodeU);
    if (!allowsSelfLoops && nodeU == nodeV) { // just an optimization, only check reference equality
      return ImmutableSet.of();
    }
    checkArgument(containsNode(nodeV), NODE_NOT_IN_GRAPH, nodeV);
    return nodePairInvalidatableSet(connectionsU.edgesConnecting(nodeV), nodeU, nodeV);
  }

borderLeftWidth,\n    width: childrenRect.width,\n    height: childrenRect.height,\n  });\n  offsets.marginTop = 0;\n  offsets.marginLeft = 0;\n\n  // Subtract margins of documentElement in case it's being used as parent\n  // we do this only on HTML because it's the only element that behaves\n  // differently when margins are applied to it. The margins are included in\n  // the box of the documentElement, in the other cases not.\n  if (!isIE10 && isHTML) {\n    const marginTop = parseFloat(styles.marginTop);\n...

        if (problems instanceof DefaultModelProblemCollector) {
            return ((DefaultModelProblemCollector) problems).hasErrors();
        } else {
            // the default execution path only knows the DefaultModelProblemCollector,
            // only reason it's not in signature is because it's package private
            throw new IllegalStateException();
        }
    }

// (only the config that are of concern to minio)
func (s *peerRESTServer) GetSysConfigHandler(_ *grid.MSS) (*grid.JSON[madmin.SysConfig], *grid.RemoteErr) {
	info := madmin.GetSysConfig(context.Background(), globalLocalNodeName)
	return madminSysConfig.NewJSONWith(&info), nil
}

// GetSysServicesHandler - returns system services information.
// (only the services that are of concern to minio)