Storing custom values on RVSourceGroup

RV
1

What’s a quick snippet on how to store a custom string value on a RVSourceGroup node please?
ie this gives the "invalid property name " error

import rv
source = rv.commands.addSourceVerbose(["abc.jpg"])
source_group = rv.commands.nodeGroup(source)
custom_property = source_group + ".custom.valueA"
rv.commands.setStringProperty(custom_property, ["test"])
2

Here quick example of creating and setting a custom property

import rv
source = rv.commands.addSourceVerbose(["abc.jpg"])
source_group = rv.commands.nodeGroup(source)

propName = "%s.tags.counter" % source_group
if not rv.commands.propertyExists(propName):
    rv.commands.newProperty(propName, rv.commands.IntType, 1)
rv.commands.setIntProperty(propName, [22], True)
print (rv.commands.getIntProperty(propName))