Diffie-Hellman Group 20 is missing in config parser for Cisco IOS

[empusas]

Device is a cisco router with IOS-XE version 15.5

Config section:

crypto map CMAP-CVG 10 ipsec-isakmp
 set peer 172.17.211.55
 set transform-set TS-CVG
 set pfs group20
 set ikev2-profile PROF-CVG 
 match address CVG-IPSEC

Error Message

org.batfish.common.BatfishException: Could not convert to DiffieHellmanGroup: group20\n\tat org.batfish.grammar.cisco.CiscoControlPlaneExtractor.convError(CiscoControlPlaneExtractor.java:1542)\n\tat org.batfish.grammar.cisco.CiscoControlPlaneExtractor.toDhGroup(CiscoControlPlaneExtractor.java:9397)\n\tat org.batfish.grammar.cisco.CiscoControlPlaneExtractor.exitCrypto_map_t_ii_set_pfs(CiscoControlPlaneExtractor.java:4182)\n\tat org.batfish.grammar.cisco.CiscoParser$Crypto_map_t_ii_set_pfsContext.exitRule(CiscoParser.java)\n\tat org.batfish.grammar.BatfishParseTreeWalker.exitRule(BatfishParseTreeWalker.java:42)\n\tat org.antlr.v4.runtime.tree.ParseTreeWalker.walk(ParseTreeWalker.java:30)\n\tat org.antlr.v4.runtime.tree.ParseTreeWalker.walk(ParseTreeWalker.java:28)\n\tat org.antlr.v4.runtime.tree.ParseTreeWalker.walk(ParseTreeWalker.java:28)\n\tat org.antlr.v4.runtime.tree.ParseTreeWalker.walk(ParseTreeWalker.java:28)\n\tat org.antlr.v4.runtime.tree.ParseTreeWalker.walk(ParseTreeWalker.java:28)\n\tat org.antlr.v4.runtime.tree.ParseTreeWalker.walk(ParseTreeWalker.java:28)\n\tat org.antlr.v4.runtime.tree.ParseTreeWalker.walk(ParseTreeWalker.java:28)\n\tat org.antlr.v4.runtime.tree.ParseTreeWalker.walk(ParseTreeWalker.java:28)\n\tat org.batfish.grammar.cisco.CiscoControlPlaneExtractor.processParseTree(CiscoControlPlaneExtractor.java:9312)\n\tat org.batfish.job.ParseVendorConfigurationJob.parseFile(ParseVendorConfigurationJob.java:438)\n\tat org.batfish.job.ParseVendorConfigurationJob.parse(ParseVendorConfigurationJob.java:538)\n\tat org.batfish.main.Batfish.getOrParse(Batfish.java:2622)\n\tat org.batfish.main.Batfish.lambda$serializeNetworkConfigs$44(Batfish.java:2700)\n\tat java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)\n\tat java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1655)\n\tat java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)\n\tat java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)\n\tat java.base/java.util.stream.ReduceOps$ReduceTask.doLeaf(ReduceOps.java:952)\n\tat java.base/java.util.stream.ReduceOps$ReduceTask.doLeaf(ReduceOps.java:926)\n\tat java.base/java.util.stream.AbstractTask.compute(AbstractTask.java:327)\n\tat java.base/java.util.concurrent.CountedCompleter.exec(CountedCompleter.java:746)\n\tat java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)\n\tat java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1020)\n\tat java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1656)\n\tat java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1594)\n\tat java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:183)\n

Code Segment from CiscoControlPlaneExtractor.java:

  private DiffieHellmanGroup toDhGroup(Dh_groupContext ctx) {
    if (ctx.GROUP1() != null) {
      return DiffieHellmanGroup.GROUP1;
    } else if (ctx.GROUP14() != null) {
      return DiffieHellmanGroup.GROUP14;
    } else if (ctx.GROUP15() != null) {
      return DiffieHellmanGroup.GROUP15;
    } else if (ctx.GROUP16() != null) {
      return DiffieHellmanGroup.GROUP16;
    } else if (ctx.GROUP19() != null) {
      return DiffieHellmanGroup.GROUP19;
    } else if (ctx.GROUP2() != null) {
      return DiffieHellmanGroup.GROUP2;
    } else if (ctx.GROUP21() != null) {
      return DiffieHellmanGroup.GROUP21;
    } else if (ctx.GROUP24() != null) {
      return DiffieHellmanGroup.GROUP24;
    } else if (ctx.GROUP5() != null) {
      return DiffieHellmanGroup.GROUP5;
    } else {
      throw convError(DiffieHellmanGroup.class, ctx);
    }
  }

Definition of DH Groups:

Diffie-Hellman groups 5,14,19,20, or 24 for encryption or authentication algorithms with a 128-bit key,
Diffie-Hellman group 21 for encryption or authentication algorithms with a key length of 256 bits or greater.

Diffie-Hellman group 1 - 768 bit modulus
Diffie-Hellman group 2 - 1024 bit modulus
Diffie-Hellman group 5 - 1536 bit modulus
Diffie-Hellman group 14 - 2048 bit modulus
Diffie-Hellman group 19 - 256 bit elliptic curve
Diffie-Hellman group 20 - 384 bit elliptic curve
Diffie-Hellman group 21 - 521 bit elliptic curve
Diffie-Hellman group 24 - modular exponentiation group with a 2048-bit modulus and 256-bit prime order subgroup