Factors are coerced to numeric on print

[dereckmezquita]

# Define a basic interface
SimpleDataset <- interface("SimpleDataset",
    id = "integer",
    value = "numeric",
    category = "factor"
)

# Implement the interface
valid_data <- implement(SimpleDataset,
    id = 1L,
    value = 10.5,
    category = factor("A", levels = c("A", "B", "C"))
)

print(valid_data)
#> Object implementing SimpleDataset interface:
#>   id: 1 
#>   value: 10.5 
#>   category: 1 
#> Validation on access: Enabled