how to use IgnoreUnnamedModuleForSplitPackage

[huige007]

As described in title, how can i enable feature IgnoreUnnamedModuleForSplitPackage. Because I got following error msg in vscode-java(redhat.java)
The package java.util.concurrent is accessible from more than one module: , java.base

after I set the java.jdt.ls.java.home to jdk8, above error msg disappeared

[iloveeclipse]

If we would be in Eclipse, adding line below to <project>/.settings/org.eclipse.jdt.core.prefs would do the trick.
No idea what need to be done in VS Code.

org.eclipse.jdt.core.compiler.ignoreUnnamedModuleForSplitPackage=enabled