Missing method isless(::String, ::Nullable{String})?

question

#1

While learning DataFrames.jl I experienced an issue with one of the examples I found in the documentation:

using DataFrames, Query

df = DataFrame(name=["John", "Sally", "Roger"], age=[54., 34., 79.], children=[0, 2, 4])

@from i in df begin
     @where i.name > "John"
     @select {i.name}
     @collect DataFrame
end

@from i in df begin
     @where get(i.name) > "John"
     @select {i.name}
     @collect DataFrame
end

The first query results in the following error: ERROR: MethodError: no method matching isless(::String, ::Nullable{String}) and it can be made behave correctly (see second query) by using get(i.name) instead of i.name.

Is this behavior to be expected or is isless(::String, ::Nullable{String}) missing?