code: function trim(nodes, compressor, first_in_statement$$1) {
                var len = nodes.length;
                if (!len) return null;
                var ret = [], changed = false;
                for (var i = 0; i < len; i++) {
                    var node = nodes[i].drop_side_effect_free(compressor, first_in_statement$$1);
                    changed |= node !== nodes[i];
                    if (node) {
                        ret.push(node);
                        first_in_statement$$1 = false;
                    }
                }
                return changed ? ret.length ? ret : null : nodes;
            }
docs: Drop side-effect-free elements from an array of expressions. Returns an array of expressions with side-effects or null if all elements were dropped. Note: original array may be returned if nothing changed.