Call chain analysis exception

Hello, I'm not familiar with `isAdditionalFlowStep`, so there might be some issues with the rule I wrote. Could you please help me take a look?
```java
public class HashMap extends AbstractMap
// 4、key
implements Map, Cloneable, Serializable {
static final int hash(Object key) {
int h;
// 5、key.hashCode()
return (key == null) ? 0 : (h = key.hashCode()) ^ (h >>> 16);
}

//1、s
private void readObject(java.io.ObjectInputStream s)
throws IOException, ClassNotFoundException {
s.defaultReadObject();
reinitialize();
if (loadFactor <= 0 || Float.isNaN(loadFactor))
throw new InvalidObjectException("Illegal load factor: " +
loadFactor);
s.readInt();
int mappings = s.readInt();
if (mappings < 0)
throw new InvalidObjectException("Illegal mappings count: " +
mappings);
else if (mappings > 0) {
float lf = Math.min(Math.max(0.25f, loadFactor), 4.0f);
float fc = (float)mappings / lf + 1.0f;
int cap = ((fc < DEFAULT_INITIAL_CAPACITY) ?
DEFAULT_INITIAL_CAPACITY :
(fc >= MAXIMUM_CAPACITY) ?
MAXIMUM_CAPACITY :
tableSizeFor((int)fc));
float ft = (float)cap * lf;
threshold = ((cap < MAXIMUM_CAPACITY && ft < MAXIMUM_CAPACITY) ?
(int)ft : Integer.MAX_VALUE);
@SuppressWarnings({"rawtypes","unchecked"})
Node[] tab = (Node[])new Node[cap];
table = tab;

for (int i = 0; i < mappings; i++) {
@SuppressWarnings("unchecked")
// 2、keu
K key = (K) s.readObject();
@SuppressWarnings("unchecked")
V value = (V) s.readObject();
// 3、hash(key)
putVal(hash(key), key, value, false, false);
}
}
}
}

public final class URL implements java.io.Serializable {

transient URLStreamHandler handler;

// 6
public synchronized int hashCode() {
if (hashCode != -1)
return hashCode;

// 7、handler.hashCode(this)
hashCode = handler.hashCode(this);
return hashCode;
}
}

public abstract class URLStreamHandler {

// 8、u
protected int hashCode(URL u) {
int h = 0;

String protocol = u.getProtocol();
if (protocol != null)
h += protocol.hashCode();

// 9、getHostAddress(u);
InetAddress addr = getHostAddress(u);
if (addr != null) {
h += addr.hashCode();
} else {
String host = u.getHost();
if (host != null)
h += host.toLowerCase().hashCode();
}

String file = u.getFile();
if (file != null)
h += file.hashCode();

if (u.getPort() == -1)
h += getDefaultPort();
else
h += u.getPort();

String ref = u.getRef();
if (ref != null)
h += ref.hashCode();

return h;
}
}
```

The path query from `HashMap.readObject` to `HashMap.hash->h = key.hashCode()` has been successfully completed.

```java
class ReadObjectSource extends DataFlow::Node {
ReadObjectSource() {
exists(Method m |
m.getDeclaringType().getASupertype() instanceof TypeSerializable and
m.hasName("readObject") and
m.getDeclaringType().hasQualifiedName("java.util", "HashMap") and
this.asParameter() = m.getParameter(0)
)
}
}

class GetHostAddressSource extends DataFlow::Node {
GetHostAddressSource() {
exists(MethodCall call |
call.getMethod().hasName("hashCode") and
call.getMethod().getDeclaringType().hasQualifiedName("java.lang", "Object") and
this.asExpr() = call.getQualifier()
)
}
}

module LiteralToURLConfig implements DataFlow::ConfigSig {
predicate isSource(DataFlow::Node source) {
source instanceof ReadObjectSource
}

predicate isSink(DataFlow::Node sink) {
sink instanceof GetHostAddressSource
}
}
```


However, the path from `HashMap.readObject` to `HashMap.hash->h = key.hashCode()` cannot be found as shown below, and it directly jumps to the `hashCode` method in other classes.

```java
class ReadObjectSource extends DataFlow::Node {
ReadObjectSource() {
exists(Method m |
m.getDeclaringType().getASupertype() instanceof TypeSerializable and
m.hasName("readObject") and
m.getDeclaringType().hasQualifiedName("java.util", "HashMap") and
this.asParameter() = m.getParameter(0)
)
}
}

class GetHostAddressSource extends DataFlow::Node {
GetHostAddressSource() {
exists(MethodCall call |
call.getMethod().hasName("getHostAddress") and
this.asExpr() = call.getArgument(0)
)
}
}

module LiteralToURLConfig implements DataFlow::ConfigSig {
predicate isSource(DataFlow::Node source) {
source instanceof ReadObjectSource
}

predicate isSink(DataFlow::Node sink) {
sink instanceof GetHostAddressSource
}

predicate isAdditionalFlowStep(DataFlow::Node source, DataFlow::Node sink){
source instanceof ReadObjectSource and
exists(
MethodCall call,
RefType rt
|
source instanceof ReadObjectSource and
sink.asExpr() = call.getQualifier() and
rt = sink.getType().(RefType)
)
}
}
```


Beginnen Sie mit den beiden DataFlow::ConfigSig-Beispielen im Issue und vergleichen Sie den erfolgreichen Pfad mit der fehlschlagenden isAdditionalFlowStep-Konfiguration. Verfolgen Sie, wie ReadObjectSource, GetHostAddressSource, MethodCall und RefType verwendet werden, und überprüfen Sie anschließend das Verhalten anhand der gezeigten HashMap- und URL-Aufrufkette. Die Aufgabe ist erledigt, wenn das Pfadverhalten erklärt ist und die Konfiguration entweder den beabsichtigten Pfad findet oder dokumentiert, warum dies nicht möglich ist.

Vom Indexierungsmodell aus dem Issue-Text verfasst.