Building a stack in python - input and output groups do not match error

The working example for building a stack

import rv

src1 = “https://assets.mixkit.co/videos/preview/mixkit-striking-texture-of-the-liquid-from-a-lava-lamp-51737-large.mp4 1”
src2 = “https://assets.mixkit.co/videos/preview/mixkit-strange-texture-of-a-bubbling-yellow-liquid-51732-large.mp4 1”

src1_node = rv.commands.addSourceVerbose([src1])
src2_node = rv.commands.addSourceVerbose([src2])

rv.extra_commands.setUIName(rv.commands.nodeGroup(src1_node), “src1”)
rv.extra_commands.setUIName(rv.commands.nodeGroup(src2_node), “src2”)

stack_node = rv.commands.newNode(“RVStackGroup”, “PlateStack”)
rv.commands.setNodeInputs(stack_node, [rv.commands.nodeGroup(src2_node), rv.commands.nodeGroup(src1_node)])