in reactor/Core/src/jetbrains/mps/logic/reactor/core/internal/ReteRuleMatcherImpl.kt [527:535]
fun add(signature: Signature) {
signatures.add(signature)
for (id in signature) {
if (!index.contains(id)) {
index.put(id, arrayListOf())
}
index.get(id).add(signature)
}
}