protected String getUsageString(String cmd) {
    StringBuilder result = new StringBuilder(80);
    result.append(usageMap.get("gemfire")).append(' ');
    if (cmd == null || cmd.equalsIgnoreCase("gemfire")) {
      result.append(join(Arrays.asList(validCommands), "|")).append(" ...");
    } else {
      result.append(usageMap.get(cmd.toLowerCase()));
    }
    return result.toString();
  }
Represents a list of ResourceInst that have been combined together. Note the most common case
is for this class to only own a single ResourceInst.
geode-core/src/main/java/org/apache/geode/internal/SystemAdmin.java