public SchemaBuilder addElementSchema(String index, SchemaName schema, Object origin) {
		if (index.equals("")) {
			return setDefaultElementSchema(schema);
		}
		if (elementSchemas.containsKey(index)) {
			throw new IllegalArgumentException("Duplicate element index '" + index +
				"' origin1=" + elementOrigins.get(index) +
				" origin2=" + origin);
		}
		elementSchemas.put(index, schema);
		elementOrigins.put(index, origin);
		return this;
	}
Define the schema for a child element

@param index the index whose schema to define, or "" for the default
@param schema the schema defining the element
@param origin optional, for diagnostics, an object describing the element schema's origin
@return this builder
Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/model/target/schema/SchemaBuilder.java