public boolean packageExists(ModuleSymbol msym, Name fullname) {
        Assert.checkNonNull(msym);
        return lookupPackage(msym, fullname).exists();
    }
public boolean packageExists ( ModuleSymbol msym , Name fullname ) { Assert . checkNonNull ( msym ) ; return lookupPackage ( msym , fullname ) . exists ( ) ; }
Check to see if a package exists, given its fully qualified name.