docs: function set( keypath, value, options ) {
  	/* jshint validthis:true */
  	var opts = {};
  	if ( arguments.length > 2 ) {
  		if ( !isObject( options ) ) {
  			throw new TypeError( 'invalid input argument. Options argument must be an object. Value: `' + options + '`.' );
  		}
  		if ( options.hasOwnProperty( 'sep' ) ) {
  			opts.sep = options.sep;
  		}
  		if ( options.hasOwnProperty( 'create' ) ) {
  			opts.create = options.create;
  		}
  	}
  	if ( opts.sep === void 0 ) {
  		opts.sep = this._opts.sep;
  	}
  	if ( opts.create === void 0 ) {
  		opts.create = this._opts.create;
  	}
  	return deepSet( this._db, keypath, value, opts );
  }