Print the contents of an exdf object
print.exdf.RdPrints the contents of an exdf object's main_data. Each column
  is described by its name, unit, and category formatted like
  name [category] (units).
Usage
# S3 method for class 'exdf'
print(x, ...)Examples
simple_exdf <- exdf(data.frame(A = 1), data.frame(A = 'u'), data.frame(A = 'c'))
print(simple_exdf)
#> 
#> Converting an `exdf` object to a `data.frame` before printing
#> 
#>   A [c] (u)
#> 1         1