dv = DataVector[1, 2, NA]
dm = DataArray([1 2; 3 4])
dt = datazeros(2, 2, 2)

df = DataFrame(quote
                 A = 1:2
                 B = 2:3
               end)

for el in dv
    @assert ndims(el) == 0
end

for el in dm
    @assert ndims(el) == 0
end

for el in dt
    @assert ndims(el) == 0
end

for row in EachRow(df)
    @assert isa(row, DataFrame)
end

for col in EachCol(df)
    @assert isa(col, AbstractDataVector)
end

@assert isequal(map(x -> min(matrix(x)), EachRow(df)), {1,2})
@assert isequal(map(min, EachCol(df)), DataFrame(quote A = 1; B = 2 end))

# @test_fail for x in df; end # Raises an error
