code: def _get_jvm_opts(config, tmp_dir):
      
      resources = config_utils.get_resources("varscan", config)
      jvm_opts = resources.get("jvm_opts", ["-Xmx750m", "-Xmx2g"])
      jvm_opts = config_utils.adjust_opts(jvm_opts,
                                          {"algorithm": {"memory_adjust":
                                                         {"magnitude": 1.1, "direction": "decrease"}}})
      jvm_opts += ["-Duser.language=en", "-Duser.country=US"]
      jvm_opts += broad.get_default_jvm_opts(tmp_dir)
      return " ".join(jvm_opts)
docs: Retrieve common options for running VarScan.
      Handles jvm_opts, setting user and country to English to avoid issues
      with different locales producing non-compliant VCF.