code: function (mQueryOptions, oType) {
  			if (oType && oType.$Key) {
  				_Helper.addToSelect(mQueryOptions, oType.$Key.map(function (vKey) {
  					if (typeof vKey === "object") {
  						return vKey[Object.keys(vKey)[0]];
  					}
  					return vKey;
  				}));
  			}
  		}
docs: Adds the key properties of the given entity type to $select of the given query options.
  
  @param {object} mQueryOptions
  The query options
  @param {object} oType
  The entity type's metadata "JSON"