    xychart
        title bla_x-axis bla
        %%        ~~~~~~ keyword...
        title "bla_x-axis bla"
        x-axis ds [jan0, d, _vertical-line, Bvertical]
        %%                   ~~~~~~~~ ~~~~ keyword
        x-axis ds ["_vertical-line","Bvertical-line"]
        y-axis x-axis_-20.22 --> 50
        %%           ^^ no sep between title and min
        y-axis "x-axis_"-20.22 --> 50
        y-axis x-axis-20.22 --> 50
        %%     ^^^^^^ keyword...
        y-axis "x-axis" -20.22 --> 50
        bar [22, 23]