def apply(configuration : WindowConfiguration) : Bool #

def configure(title : String, subtitle : String | Nil = nil, preferred_width : Float64 | Nil = nil, preferred_height : Float64 | Nil = nil, minimum_width : Float64 | Nil = nil, minimum_height : Float64 | Nil = nil, maximum_width : Float64 | Nil = nil, maximum_height : Float64 | Nil = nil, titlebar_style : WindowTitlebarStyle = WindowTitlebarStyle::Standard, shows_titlebar : Bool = true, shows_toolbar : Bool = true, allows_full_screen : Bool = true, resizable : Bool = true) : WindowConfiguration #