code: public void setModelType(ModelType type) {
  		this.modelType = type;
  
  		if (type != ModelType.AUTO) {
  			this.type = type.getJsName();
  		}
  		else {
  			this.type = null;
  		}
  	}
docs: Type of the field. Property '
  <a href="http://docs.sencha.com/ext-js/4-2/#!/api/Ext.data.Field-cfg-type" >type
  </a>' in JS.
  
  @param type new type for the field