@Test
public void mapToJsonStringKeys() {

    Schema stringIntMap = SchemaBuilder.map(Schema.STRING_SCHEMA, Schema.INT32_SCHEMA).build();
    Map<String, Integer> input = new HashMap<>();
    input.put("key1", 12);
    input.put("key2", 15);
    JsonNode converted = parse(converter.fromConnectData(TOPIC, stringIntMap, input));
    validateEnvelope(converted);
    assertEquals(parse("{ \"type\": \"map\", \"keys\": { \"type\" : \"string\", \"optional\": false }, \"values\": { \"type\" : \"int32\", \"optional\": false }, \"optional\": false }"),
            converted.get(JsonSchema.ENVELOPE_SCHEMA_FIELD_NAME));
    assertEquals(JsonNodeFactory.instance.objectNode().put("key1", 12).put("key2", 15),
            converted.get(JsonSchema.ENVELOPE_PAYLOAD_FIELD_NAME));
}