public static PropertiesDescriptor <T> Int64 <T>(this PropertiesDescriptor <T> propertiesDescriptor, Func <NumberPropertyDescriptor <T>, INumberProperty> selector) where T : class { // Validate parameters. if (propertiesDescriptor == null) { throw new ArgumentNullException(nameof(propertiesDescriptor)); } if (selector == null) { throw new ArgumentNullException(nameof(selector)); } // Modify and return. return(propertiesDescriptor.NumberProperty(selector, NumberType.Long)); }