Function radial

pub fn radial<'a>(
    center: impl Into<Point>,
    radius: scalar,
    colors: impl Into<GradientShaderColors<'a>>,
    pos: impl Into<Option<&'a [scalar]>>,
    mode: TileMode,
    flags: impl Into<Option<Flags>>,
    local_matrix: impl Into<Option<&'a Matrix>>,
) -> Option<Shader>