Prepares a 'wide' data frame into a format that `geom_sankey` or `geom_alluvial` understands. Useful to show flows between dimensions in dataset.
     
    
    Usage
    make_long(.df, ..., value = NULL)
 
    
    Arguments
- .df
- a data frame 
- ...
- unquoted columnnames of df that you want to include in the plot. 
- value
- if each row have a weight this weight could be kept by providing column name of weight. 
 
    
    Value
    a longer data frame