code: function newCustomPostOne(endpoint, initParams, allowable) {
      var modify = newPostOne(endpoint, allowable);
      return function(body, callback) {
          _.assign(body, initParams);
          return modify.call(this, body, callback);
      };
  }
docs: Return a function for custom Post requests
  
  @param  {Endpoint} endpoint
  @param  {Object} initParams - parameters used to indicate we are infact modifying
  @param  {String[]} [allowable]
  @return {itemsPostOneRequest}