GPUParticles2D's convert_from_particles() method inputs any Node instead of a CPUParticles2D

Question

Just curious about why GPUParticles2D’s convert_from_particles() method takes a Node input instead of a CPUParticles2D. The method’s description says it ‘set’s this node’s properties to match a given CPUParticles2D node’ but it takes any node instead of just a CPUParticles2D?