How can I switch from Single Image to Image Sequence in Compositor network, with a script?

I have this piece of Python code:

import bpy
import os

# switch on nodes
bpy.context.scene.use_nodes = True
tree = bpy.context.scene.node_tree

# Clear default nodes
for node in tree.nodes:
tree.nodes.remove(node)

# Create input image node
image_node = tree.nodes.new(type='CompositorNodeImage')
file_path = "C:\\DEV\\testSequence.1114.exr"
image_node.frame_duration = 200
image_node.frame_start = 1114
image_node.frame_offset = 1114
image_node.location = 0,0


This script makes a node in the compositor tree and loads the file in C:/DEV/testSequence.1114.exr; however, instead of 'Single Image', I want to switch to 'Image Sequence'. how can do this in script?

image_node.image.source = 'SEQUENCE'