When KeyAgreement#init(Key,AlgorithmParameterSpec) is called with null
AlgorithmParameterSpec, then XDH based algorithm is throwing InvalidAlgorithmParameterException but other algorithm say "ECDH" "EC" are accepting the null values
======================XDH ==================================
jshell> import java.security.*
jshell> import java.security.spec.*
jshell> import javax.crypto.*

jshell> KeyAgreement ka = KeyAgreement.getInstance("XDH");
ka ==> javax.crypto.KeyAgreement@57855c9a

jshell> KeyPairGenerator kpg = KeyPairGenerator.getInstance("XDH");
kpg ==> java.security.KeyPairGenerator$Delegate@7f13d6e

jshell> KeyPair kp = kpg.generateKeyPair();
kp ==> java.security.KeyPair@704a52ec

jshell> ka.init(kp.getPrivate(),(AlgorithmParameterSpec)null);
| Exception java.security.InvalidAlgorithmParameterException: Only NamedParameterSpec is supported.
| at XECParameters.get (XECParameters.java:259)
| at XDHKeyAgreement.engineInit (XDHKeyAgreement.java:73)
| at KeyAgreement.implInit (KeyAgreement.java:356)
| at KeyAgreement.chooseProvider (KeyAgreement.java:386)
| at KeyAgreement.init (KeyAgreement.java:547)
| at KeyAgreement.init (KeyAgreement.java:517)
| at (#7:1)
==========================NULL SecureRandom==============================
Suppose "SecureRandom" is null it is accepted

jshell> ka.init(kp.getPrivate(),(SecureRandom)null); //accepted adheres with ECDH behavior

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If you were to change the "XDH" to say "ECDH" and "EC"(keys) then null is accepted and not throwing InvalidAlgorithmParameterException
===========ECDH / EC==============================
jshell> KeyAgreement ka = KeyAgreement.getInstance("ECDH");
ka ==> javax.crypto.KeyAgreement@30b8a058

jshell> KeyPairGenerator kpg = KeyPairGenerator.getInstance("EC");
kpg ==> java.security.KeyPairGenerator$Delegate@4f063c0a

jshell> kpg.initialize(571)

jshell> KeyPair keypair = kpg.generateKeyPair();
keypair ==> java.security.KeyPair@2d8f65a4

jshell> ka.init(keypair.getPrivate(),(AlgorithmParameterSpec) null); // accepting no error.
ka.init(keypair.getPrivate(),(SecureRandom) null); //accepted no errror
=====================================================

I believe the specification does not state anything about null AlgorithmParameterSpec and behavior should be consistent across different algorithms.

Please clarify the spec to mention about scenario when null is passed to AlgorithmParameterSpec