Line

#Array methods
line(x::AbstractVector, y::AbstractVector{<:Union{Missing, Real}})
line(x::AbstractVector, y::AbstractArray{<:Union{Missing, Real}, 2})

#DataFrame methods
line(df::AbstractDataFrame, x::Symbol, y::Symbol)
line(df::AbstractDataFrame, x::Symbol, y::Symbol, group::Symbol)

step::Union{String, Void} = nothing #choice of {"start", "middle", "end"}
legend::Bool = false
scale::Bool = false
kwargs... #modifies top-level `EChart` fields

using ECharts
x = ["Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"]
y = [11, 11, 15, 13, 12, 13, 10]
l = line(x, y)

using ECharts
x = ["Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"]
y = [11, 11, 15, 13, 12, 13, 10]
ls = line(x, y, step = "end")

using ECharts
x = ["Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"]
y = [11, 11, 15, 13, 12, 13, 10]
y2 = 0.6 .* y
l2s = line(x, hcat(y, y2))

using ECharts, DataFrames
x = [0,1,2,3,4,5,6,7,8,9,0,1,2,3,4,5,6,7,8,9]
y = [28, 43, 81, 19, 52, 24, 87, 17, 68, 49, 55, 91, 53, 87, 48, 49, 66, 27, 16, 15]
g = [0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1]
df_merged = DataFrame(x = x, y = y, g = g)
ldf = line(df_merged, :x, :y, :g)