code: function(...a_args) {
  
  		// ref args length and 0th arg
  		let n_args = a_args.length;
  		let z_arg0 = a_args[0];
  
  		// no arguments OR single argument is a boolean (fetch)
  		if(n_args === 0 || (n_args === 1 && 'boolean' === typeof z_arg0)) {
  
  			// no soft/hard options
  			if('function' === typeof h_handler.fetch) {
  				return h_handler.fetch();
  			}
  			// fetch soft
  			else if(!n_args || false === z_arg0) {
  				return h_handler.fetch.soft();
  			}
  			// fetch hard
  			else {
  				return h_handler.fetch.hard();
  			}
  		}
  		// add
  		else {
  			h_handler.add(...a_args);
  		}
  
  		// update self reference to this
  		self = this;
  
  		// chain
  		return this;
  	}
docs: interface function