Match part of custom_data component in a predicate

Heya, I have a predicate which should just test for whether {be:1b} exists inside the held item's custom_data component. However, the predicate only runs if the custom_data of the item matches exactly what is specified in the predicate. How do I make it only check if the component includes the data, and not if it matches exactly? This is the predicate:json { "condition": "minecraft:entity_properties", "entity": "this", "predicate": { "equipment": { "mainhand": { "items": "minecraft:snowball", "components": { "minecraft:custom_data": {"be":1} } } } } }