@Test
public void mapToConnectStringKeys() {

    byte[] mapJson = "{ \"schema\": { \"type\": \"map\", \"keys\": { \"type\" : \"string\" }, \"values\": { \"type\" : \"int32\" } }, \"payload\": { \"key1\": 12, \"key2\": 15} }".getBytes();
    Map<String, Integer> expected = new HashMap<>();
    expected.put("key1", 12);
    expected.put("key2", 15);
    assertEquals(new SchemaAndValue(SchemaBuilder.map(Schema.STRING_SCHEMA, Schema.INT32_SCHEMA).build(), expected), converter.toConnectData(TOPIC, mapJson));
}