text: var mongoose = require('mongoose');
  
  var BalanceSchema = new mongoose.Schema({
    _id       : Number,
    corporation: { type: Number, ref: 'Corporation'},
    timestamp : { type: Date, default: Date.now },
    vd_balance: Number,
    vg_balance: Number
  });
  
  module.exports = mongoose.model('Balance', BalanceSchema);
  