* nuframe in its own type in UntaggedValue
* Removed eager dataframe from enum
* Dataframe created from list of values
* Corrected order in dataframe columns
* Returned tag from stream collection
* Removed series from dataframe commands
* Arithmetic operators
* forced push
* forced push
* Replace all command
* String commands
* appending operations with dfs
* Testing suite for dataframes
* Unit test for dataframe commands
* improved equality for dataframes
