public Schema getRootSchema() {
        return rootSchema;
    }
Gets the root schema definition.

@return Returns the root schema.
@see <a href="https://json-schema.org/latest/json-schema-core.html#rfc.section.4.3.3">Root schema</a>
smithy-jsonschema/src/main/java/software/amazon/smithy/jsonschema/SchemaDocument.java