I have a question regarding flexibility - in the lecture there is an example to show how the document model can flexibily change over time. THe example shows “Phone”: 888888 and then over time it changes to array of numbers. So change the data type is possible and also this leads to multiple versions of the schema. Is it the case that the both the versions of the schema co-exist. i.e., if i have data pipeline that supports version 1 and another newer data pipeline that supports version 2 both can be still valid? I dont need to update my version 1 data pipeline to confirm to version 2 data model?