onemit.js
function _extend(obj, from) {
        for ( let key in from ) if ( hop.call(from, key) ) {
            obj[key] = from[key];
        }
        return obj;
    }
function _extend(obj, from) {
        for ( let key in from ) if ( hop.call(from, key) ) {
            obj[key] = from[key];
        }
        return obj;
    }
function _extend ( obj , from ) { for ( let key in from ) if ( hop . call ( from , key ) ) { obj [ key ] = from [ key ] ; } return obj ; }
Copy properties to `obj` from `from`

@param  (Object) obj
@param  (Object) from - source object

@return (Object) obj
@api private
Copy properties to obj from from