code: function( default_connection_index ){
      LoadBalancingPolicy.apply(this,Array.prototype.slice.call(arguments));
      this._default_connection_index = default_connection_index || 0;
  }
docs: SingleNodePolicy constructor
  @param {int} default_connection_index Order of host as defined in Apollo constructor
  @class SingleNodePolicy
  @extends LoadBalancingPolicy
  @classDesc With this policy only one host will be used for communication