anchor.diff:  ///   * [PaletteTarget], to be able to create your own target color types.
   ///   * [PaletteFilter], a function signature for filtering the allowed colors
   ///     in the palette.
  -class PaletteGenerator with DiagnosticableMixin {
  +class PaletteGenerator with Diagnosticable {
     /// Create a [PaletteGenerator] from a set of paletteColors and targets.
     ///
     /// The usual way to create a [PaletteGenerator] is to use the asynchronous
  
positive.code: /// See also:
  ///
  ///   * [PaletteGenerator], a class for selecting color palettes from images.
  class PaletteTarget with DiagnosticableMixin {
    /// Creates a [PaletteTarget] for custom palette selection.
    ///
    /// None of the arguments can be null.
  
negative.code: /// See also:
  ///
  ///   * [PaletteGenerator], a class for selecting color palettes from images.
  class PaletteColor with Diagnosticable {
    /// Generate a [PaletteColor].
    ///
    /// The `color` and `population` parameters must not be null.
  