How to make preset for RGB curves in compositor i have added preset base in my code, now is there any way to save data of RGB curve , so we can use it from saved dropdown menu at any time in any file , 

i have added preset base 

this gives me only 1 point data , it does save it but only one , if i add extra points and then save it as preset even after that it didnt count extra curvepoints , it only gives x and y values of single point 

do let me know if there are any way to save RGB curve property for compositor 

class add_comp_preset(AddPresetBase, bpy.types.Operator):
"""Add a new render preset."""
bl_idname = 'comp.add'
bl_label = 'Add My comp Preset'
bl_options = {'REGISTER', 'UNDO'}
preset_menu = 'comp_presets'
preset_subdir = 'weybec_comp_preset'





preset_defines = [
    "nc  = bpy.context.scene.nc",
    "scene  = bpy.context.scene",
    "render = bpy.context.scene.render",
    ""for i in bpy.data.node_groups['nevercomp'].nodes['RGB'].mapping.curves[3].points:c = i.location"

preset_values = [
    'c'
    ]
The properties of every point of RGB curves node can be accessed using the following snippet. Generally, the location of the point in XY plane is useful. Hence to access that property:

(RGB_Curves_Node).mapping.curves[0].points[id].location_x


Similarly,

(RGB_Curves_Node).mapping.curves[0].points[id].location_y


id is used to access which point you want the property from. Also, the 'R', 'G', 'B' and 'C' curves are separated by id 0, 1, 2, 3 respectively.

As you want to save the data as a preset, you would probably want to do something like

preset = [[], [], [], []]
for i in range(0, 5):
    for point in bpy.context.scene.node_tree.nodes['RGB'].mapping.curves[i].points:
       preset[i].append((point.location.x, point.location.y))