public void insert(String string) {
            var node = this;

            for (var c : string.toCharArray()) {
                node = node.children.computeIfAbsent(c, k -> new TrieNode());
            }

            node.isEndOfString = true;
        }
Converts a JSON Schema to a GBNF grammar to be used for structured output with llama.cpp.
It is a port of Python implementation from llama.cpp repository.
Current implementation doesn't support regex patterns, resolving $ref or fetching schemas from URLs.
The plan is to replace this with C++ implementation from llama.cpp though JNI.
model-integration/src/main/java/ai/vespa/llm/clients/JsonSchemaToGrammar.java