FreeswitchUtil.prototype.runFreeswitchCommand = function(command, callback, FS) {
  callback = callback ? callback : function() {};
  FS = FS ? FS : this.FS;
  this.logger.debug(format("Running command '%s'", command));
  FS.api(command)
  .then(function(res) {
    this.logger.debug(format("Command '%s' result headers: %s", command, JSON.stringify(res.headers)));
    this.logger.debug(format("Command '%s' result body: %s", command, res.body));
    callback(null, res.body);
  }.bind(this))
  .catch(function(error) {
    if (_.isObject(error.res)) {
      this.logger.error(format("Command '%s' error: %s", command, error.res.body));
      callback(error.res.body, null);
    }
    else {
      this.logger.error(format("Command '%s' error: %s", command, JSON.stringify(error)));
      callback(error, null);
    }
  }.bind(this));
}