function Summary() {
    BackboneFile.apply(this, arguments);

    this.parts = [];
    this._length = 0;
}
/*
A summary is composed of a list of parts, each composed wit a tree of articles.
*/
A summary is composed of a list of parts, each composed wit a tree of articles.
A summary is composed of a list of parts each composed wit a tree of articles .
function Summary() {
    BackboneFile.apply(this, arguments);
    this.parts = [];
    this._length = 0;
}
function Summary ( ) { BackboneFile . apply ( this , arguments ) ; this . parts = [ ] ; this . _length = 0 ; }
A summary is composed of a list of parts, each composed wit a tree of articles.
A summary is composed of a list of parts each composed wit a tree of articles .