method for getting a defined model

lib/sequelize/model-manager.js

@@ -15,6 +15,13 @@ ModelManager.prototype.removeModel = function(model) {
   })
   })
 }
 }
 
 
+ModelManager.prototype.getModel = function(modelName) {
+  var model = this.models.filter(function(model) {
+    return model.name == modelName
+  })
+  return !!model ? model[0] : null
+}
+
 ModelManager.prototype.__defineGetter__('all', function() {
 ModelManager.prototype.__defineGetter__('all', function() {
   return this.models
   return this.models
-})
+})
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