public int getNumExecutors() {
   try {
     return Integer.parseInt(numExecutors);
   } catch (NumberFormatException e) {
     return EC2AbstractSlave.toNumExecutors(type);
   }
 }
 public ListBoxModel doFillZoneItems(
     @QueryParameter boolean useInstanceProfileForCredentials,
     @QueryParameter String credentialsId,
     @QueryParameter String region)
     throws IOException, ServletException {
   AWSCredentialsProvider credentialsProvider =
       EC2Cloud.createCredentialsProvider(useInstanceProfileForCredentials, credentialsId);
   return EC2AbstractSlave.fillZoneItems(credentialsProvider, region);
 }
  /**
   * Determines whether the AMI of the given instance matches the AMI of template and has the
   * required label (if requiredLabel is non-null)
   */
  private boolean checkInstance(
      PrintStream logger,
      Instance existingInstance,
      Label requiredLabel,
      EC2AbstractSlave[] returnNode) {
    logProvision(logger, "checkInstance: " + existingInstance);
    if (StringUtils.isNotBlank(getIamInstanceProfile())) {
      if (existingInstance.getIamInstanceProfile() != null) {
        if (!existingInstance.getIamInstanceProfile().getArn().equals(getIamInstanceProfile())) {
          logProvision(logger, " false - IAM Instance profile does not match");
          return false;
        }
        // Match, fall through
      } else {
        logProvision(logger, " false - Null IAM Instance profile");
        return false;
      }
    }

    if (existingInstance
            .getState()
            .getName()
            .equalsIgnoreCase(InstanceStateName.Terminated.toString())
        || existingInstance
            .getState()
            .getName()
            .equalsIgnoreCase(InstanceStateName.ShuttingDown.toString())) {
      logProvision(logger, " false - Instance is terminated or shutting down");
      return false;
    }
    // See if we know about this and it has capacity
    for (EC2AbstractSlave node : NodeIterator.nodes(EC2AbstractSlave.class)) {
      if (node.getInstanceId().equals(existingInstance.getInstanceId())) {
        logProvision(logger, "Found existing corresponding Jenkins slave: " + node.getInstanceId());
        if (!node.toComputer().isPartiallyIdle()) {
          logProvision(logger, " false - Node is not partially idle");
          return false;
        }
        // REMOVEME - this was added to force provision to work, but might not allow
        // stopped instances to be found - need to investigate further
        else if (false && node.toComputer().isOffline()) {
          logProvision(logger, " false - Node is offline");
          return false;
        } else if (requiredLabel != null && !requiredLabel.matches(node.getAssignedLabels())) {
          logProvision(logger, " false - we need a Node having label " + requiredLabel);
          return false;
        } else {
          logProvision(logger, " true - Node has capacity - can use it");
          returnNode[0] = node;
          return true;
        }
      }
    }
    logProvision(logger, " true - Instance has no node, but can be used");
    return true;
  }