function createDocPost(doc, callback) {
        this.db.post(doc, function (err, response) {
            if (!callback) return;
            if (err) {
                return callback(false, err);
            }
            callback(true, response);
        });
    }
/**
     *  create doc with post 
     *  PouchDB auto-generate an _id
     **/
create doc with post
PouchDB auto-generate an _id
create doc with post PouchDB auto - generate an _id
function createDocPost(doc, callback) {
        this.db.post(doc, function (err, response) {
            if (!callback) return;
            if (err) {
                return callback(false, err);
            }
            callback(true, response);
        });
    }
function createDocPost ( doc , callback ) { this . db . post ( doc , function ( err , response ) { if ( ! callback ) return ; if ( err ) { return callback ( false , err ) ; } callback ( true , response ) ; } ) ; }
create doc with post
  PouchDB auto-generate an _id
create doc with post PouchDB auto - generate an _id