Implement to create the columns. This method will be called each time the inputs of the producer changes or the GetConfigureColumnsTriggerCore fires. The purpose is to add the metadata about each output column that should be created and which inputs it has to the configurator. If this is the first call to the method those columns will be created. If there are already existing output columns those will be matched against those provided in the configurator, primarily on external id, and those no longer present will be removed, new ones added and those still remaining updated with the new information provided.

protected abstract void ConfigureColumnsCore(
	VirtualColumnsConfigurator configurator
)