Function radial
pub fn radial<'a>(
center: impl Into<Point>,
radius: f32,
colors: impl Into<GradientShaderColors<'a>>,
pos: impl Into<Option<&'a [f32]>>,
mode: SkTileMode,
flags: impl Into<Option<Flags>>,
local_matrix: impl Into<Option<&'a Matrix>>,
) -> Option<RCHandle<SkShader>>