Considering the GradientPacket.gradient to output, packet of potential
properties from both of two gradients, and the primitive of colors and
stops formed from those same two gradients:
Provide a dynamic createShader method that considers all the above to
dart:ui Shader that best represents a mix of these gradients.
GradientCopyWith overrideCopyWith = spectrumCopyWith,
}) : _copyWith = overrideCopyWith,
super(colors: primitive.colors, stops: primitive.stops);